| Team Name | Roster | League Name | Level | G | W | L | Pct | GBL | Rk | RF | RA | Diff | Manager | Ballpark |
| Seattle Mariners | Stats -- Roster | American League | MLB | 162 | 76 | 86 | .469 | 12.0 | 4 | 656 | 726 | -70 | Lloyd McClendon | Safeco Field |
| Tacoma Rainiers | Stats -- Roster | Pacific Coast League | AAA | 154 | 68 | 76 | .472 | 16.5 | 4 | 745 | 755 | -10 | Pat Listach | Cheney Stadium |
| Jackson Generals | Stats -- Roster | Southern League | AA | 139 | 53 | 84 | .387 | 23.5 | 5 | 510 | 664 | -154 | Jim Horner | The Ballpark at Jackson |
| Bakersfield Blaze | Stats -- Roster | California League | A+ | 147 | 61 | 79 | .436 | 23.0 | 5 | 567 | 629 | -62 | Eddie Menchaca | Sam Lynn Ballpark |
| Clinton LumberKings | Stats -- Roster | Midwest League | A | 132 | 46 | 93 | .331 | 42.5 | 8 | 535 | 700 | -165 | Scott Steinmann | Ashford University Field |
| Everett Aqua Sox | Stats -- Roster | Northwest League | A- | 128 | 42 | 34 | .553 | -- | 1 | 392 | 353 | +39 | Rob Mummau | Everett Memorial Stadium |
| Arizona Mariners | Stats -- Roster | Arizona League | Rk | 117 | 31 | 25 | .554 | 9.0 | 2 | 273 | 238 | +35 | Darrin Garner | Peoria Sports Complex |
| Dominican Mariners | Stats -- Roster | Dominican Summer League | Rk | 131 | 45 | 27 | .625 | 8.0 | 3 | 413 | 340 | +73 | ||
| Dominican Mariners 2 | Stats -- Roster | Dominican Summer League | Rk | 132 | 46 | 26 | .639 | 4.0 | 2 | 414 | 318 | +96 | ||
| Organizational Totals: | 998 | 468 | 530 | .469 | 23 | 4505 | 4723 | -218 | ||||||
2015 Organizational Org Roster | Top | PREV NEXT | Major Leaguers | Active Players | 1st Round Draft Picks | Still Active on Roster |
| Player Name | Pos | Team(s) | Ht | Wt | B-T | BornDate | Age | Place | HiLvl | Stat Years | MLB Years | Draft Information | College(s) | Status | Current Org (Level) |
| Dustin Ackley | 2B-CF | Seattle (MLB) | 6-1 | 182 | L-R | 1988-02-26 | 27 | Winston-Salem,North Carolina | MLB | 2007-2018 | 2011-2016 | 2009- 1- 2-SEA | North Carolina | Minors | Seattle Mariners (MLB) |
| James Alfonso | C | Clinton (A) | 5-10 | 195 | R-R | 1991-09-03 | 23 | Raynham,Massachusetts | A | 2011-2017 | - | 2014-30- 891-SEA | Hartford | Minors | Los Angeles Angels (MLB) |
| Adalfi Almonte | OF | DSL Mariners 2 (Rk) | 6-1 | 170 | R-R | 1996-04-19 | 19 | Santiago de los Caballeros,Dom Rep | RK | 2013-2016 | - | (MLB) | |||
| Dan Altavilla | P | Bakersfield (A+) | 5-11 | 200 | R-R | 1992-09-08 | 22 | McKeesport,Pennsylvania | MLB | 2014-2018 | 2016-2018 | 2014- 5- 141-SEA | Mercyhurst Col | Active | Seattle Mariners (MLB) |
| Matt Anderson | P | Jackson (AA) Tacoma (AAA) | 6-1 | 210 | R-R | 1991-11-18 | 23 | Colorado Springs,Colorado | AAA | 2012-2016 | - | 2011-41-1243-FLO | Chaffey Col, Long Beach St | Minors | Seattle Mariners (MLB) |
| Greifer Andrade | SS | DSL Mariners (Rk) | 6-0 | 170 | R-R | 1997-01-27 | 18 | Paramo Tucani,Venezuela | A | 2014-2018 | - | 2013- UDFA-SEA | Free Agent | - (MLB) | |
| Jefferson Arias | P | Everett (A-) | 6-4 | 185 | R-R | 1993-04-08 | 22 | Santo Domingo,Dom Rep | A- | 2013-2015 | - | Free Agent | (MLB) | ||
| Hector Arocha | C | DSL Mariners 2 (Rk) | 5-11 | 180 | R-R | 1997-01-15 | 18 | San Juan de los Morros,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Rayder Ascanio | SS | Clinton (A) Bakersfield (A+) | 5-11 | 155 | B-R | 1996-03-17 | 19 | Mariara,Venezuela | AAA | 2014-2018 | - | Minors | St. Louis Cardinals (A) | ||
| Brett Ash | P | Bakersfield (A+) | 6-2 | 195 | R-R | 1991-05-27 | 24 | Topeka,Kansas | AAA | 2014-2017 | - | Washburn U. | Minors | Seattle Mariners (AA) | |
| Julio Ayala | P | DSL Mariners (Rk) | 6-1 | 165 | R-R | 1997-09-17 | 17 | Villa de Cura,Venezuela | RK | 2015-2015 | - | 2014- UDFA-SEA | (MLB) | ||
| Cesar Baez | 2B | DSL Mariners 2 (Rk) | 6-0 | 160 | L-R | 1995-07-06 | 19 | Santiago,Dom Rep | RK | 2013-2015 | - | (MLB) | |||
| John Baker | C | Tacoma (AAA) | 6-1 | 220 | L-R | 1981-01-20 | 34 | Alameda,California | MLB | 2000-2015 | 2008-2014 | 2002- 4- 128-OAK | California | Free Agent | (MLB) |
| Aaron Barbosa | OF | Clinton (A) Bakersfield (A+) | 5-10 | 157 | L-R | 1992-04-14 | 23 | Dracut,Massachusetts | A+ | 2011-2016 | - | Northeastern U. | Retired | (MLB) | |
| Steven Baron | C | Jackson (AA) Tacoma (AAA) Seattle (MLB) | 6-0 | 195 | R-R | 1990-12-07 | 24 | Miami,Florida | MLB | 2009-2018 | 2015-2018 | 2009- 1- 33-SEA | Minors | Pittsburgh Pirates (MLB) | |
| Jay Baum | IF-OF | Bakersfield (A+) | 5-11 | 180 | R-R | 1992-10-25 | 22 | Alpharetta,Georgia | AA | 2012-2018 | - | 2014-21- 621-SEA | Clemson U. | Free Agent | (MLB) |
| Logan Bawcom | P | Tacoma (AAA) | 6-2 | 200 | R-R | 1988-11-02 | 26 | Midland,Texas | AAA | 2008-2018 | - | 2010-17- 532-LAN | Texas-Arlington, Midland Col | Free Agent | - (MLB) |
| Joe Beimel | P | Tacoma (AAA) Seattle (MLB) | 6-2 | 201 | L-L | 1977-04-19 | 38 | St. Mary's,Pennsylvania | MLB | 1998-2017 | 2001-2015 | 1998-18- 538-PIT | Duquesne U., Allegany Col Maryland | Free Agent | (MLB) |
| Jose Berroteran | P | DSL Mariners 2 (Rk) | 5-10 | 178 | L-L | 1994-08-03 | 20 | Miranda,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Braden Bishop | OF | Everett (A-) | 6-1 | 180 | R-R | 1993-08-22 | 21 | San Carlos,California | AA | 2013-2018 | - | 2015- 3- 94-SEA | Washington | Active | Seattle Mariners (MLB) |
| Dominic Blanco | C | Azl Mariners (Rk) | 6-2 | 215 | L-R | 1995-11-10 | 19 | Naples,Florida | A+ | 2014-2017 | - | 2014-28- 831-SEA | Free Agent | (MLB) | |
| Jabari Blash | OF | Jackson (AA) Tacoma (AAA) | 6-4 | 195 | R-R | 1989-07-04 | 25 | St. Thomas,Virgin Islands | MLB | 2009-2018 | 2016-2018 | 2010- 8- 252-SEA | Miami-Dade Col | International | (MLB) |
| Willie Bloomquist | 2B-SS | Seattle (MLB) | 5-11 | 185 | R-R | 1977-11-27 | 37 | Bremerton,Washington | MLB | 1997-2015 | 2002-2015 | 1999- 3- 95-SEA | Arizona St | Retired | (MLB) |
| Leury Bonilla | 3B | Jackson (AA) Tacoma (AAA) | 6-3 | 170 | R-R | 1985-02-08 | 30 | Gaspar,Dom Rep | AAA | 2005-2015 | - | Free Agent | (MLB) | ||
| Tyler Bortnick | 2B | Jackson (AA) | 5-10 | 180 | R-R | 1987-07-03 | 27 | Mentor,Ohio | AAA | 2006-2018 | - | 2009-16- 499-TBA | Coastal Carolina U. | Minors | Milwaukee Brewers (Rk) |
| Patrick Brady | 2B | Azl Mariners (Rk) Jackson (AA) Tacoma (AAA) | 5-10 | 175 | R-R | 1988-02-05 | 27 | Lexington,Kentucky | AAA | 2007-2017 | - | 2010-48-1452-SEA | Bellarmine U. | Free Agent | (MLB) |
| Steve Branche | SS | DSL Mariners (Rk) | 6-1 | 165 | R-R | 1997-09-01 | 17 | San Pedro de Mac,Dom Rep | RK | 2015-2018 | - | 2014- UDFA-SEA | (MLB) | ||
| Jake Brentz | P | Everett (A-) | 6-2 | 175 | L-L | 1994-09-14 | 20 | Ballwin,Missouri | AAA | 2013-2018 | - | 2013-11- 325-TOR | Minors | Pittsburgh Pirates (A+) | |
| Liarvis Breto | P | DSL Mariners (Rk) | 5-11 | 175 | L-L | 1993-04-10 | 22 | Carabobo,Venezuela | AA | 2015-2018 | - | Minors | Detroit Tigers (A+) | ||
| Kristian Brito | 1B | Clinton (A) | 6-5 | R-R | 1994-12-20 | 20 | - | A | 2012-2017 | - | 2012-11- 341-SEA | Free Agent | (MLB) | ||
| Aaron Brooks | P | Bakersfield (A+) | 6-6 | 210 | R-R | 1992-05-15 | 23 | Mountlake Terrace,Washington | AA | 2012-2017 | - | 2012-26- 791-SEA | Edmonds CC, Gonzaga U. | Free Agent | (MLB) |
| Jarrett Brown | P | Clinton (A) | 6-3 | 169 | R-L | 1992-12-15 | 22 | Conyers,Georgia | A | 2014-2015 | - | 2014-22- 651-SEA | Georgia | Free Agent | (MLB) |
| Hawtin Buchanan | P | Clinton (A) | 6-8 | 230 | R-R | 1993-04-29 | 22 | Biloxi,Mississippi | A | 2014-2017 | - | 2014-20- 591-SEA | Mississippi | Free Agent | (MLB) |
| Taylor Byrd | P | Everett (A-) | 6-2 | 175 | L-L | 1992-08-15 | 22 | Petal,Mississippi | A- | 2014-2015 | - | 2014- 7- 201-SEA | Nicholls St, Pearl River CC | Free Agent | (MLB) |
| Luis Caballero | SS | Clinton (A) Bakersfield (A+) Jackson (AA) | 6-1 | 157 | R-R | 1992-07-08 | 22 | Bocas del Toro,Panama | AA | 2010-2015 | - | Free Agent | (MLB) | ||
| Yordi Calderon | 3B | Everett (A-) | 6-2 | 185 | R-R | 1994-02-15 | 21 | Valencia,Venezuela | A- | 2013-2015 | - | Free Agent | (MLB) | ||
| Juan Camacho | C | Azl Mariners (Rk) | 6-3 | 215 | R-R | 1996-04-19 | 19 | Los Mochis,Mexico | A | 2015-2018 | - | 2014- UDFA-SEA | Minors | Seattle Mariners (A) | |
| Eddie Campbell | P | Clinton (A) Bakersfield (A+) | 6-0 | 195 | L-L | 1992-01-17 | 23 | Newton,Massachusetts | A+ | 2013-2016 | - | 2013-15- 447-SEA | Virginia Tech | Minors | Colorado Rockies (MLB) |
| Jose Cano | 3B | DSL Mariners (Rk) | 5-11 | 190 | R-R | 1996-12-18 | 18 | San Pedro de Mac,Dom Rep | RK | 2014-2018 | - | Free Agent | - (MLB) | ||
| Joselito Cano | P | Everett (A-) | 6-5 | 190 | L-L | 1992-09-16 | 22 | Carolina,Puerto Rico | A- | 2011-2016 | - | Free Agent | (MLB) | ||
| Robinson Cano | 2B | Seattle (MLB) | 6-0 | 172 | L-R | 1982-10-22 | 32 | San Pedro de Mac,Dom Rep | MLB | 2001-2018 | 2005-2018 | 2001- UDFA-NYA | Active | New York Mets (MLB) | |
| Alexander Capriata | C | Azl Mariners (Rk) | 5-11 | 190 | R-R | 1992-08-03 | 22 | Barrancas del Orinoco,Venezuela | AAA | 2011-2017 | - | Free Agent | - (MLB) | ||
| Rohimard Carrillo | P | DSL Mariners 2 (Rk) | 5-11 | 175 | R-L | 1994-08-19 | 20 | San Felix,Venezuela | RK | 2015-2016 | - | (MLB) | |||
| Welington Castillo | C | Seattle (MLB) | 6-1 | 195 | R-R | 1987-04-24 | 28 | San Isidro,Dom Rep | MLB | 2006-2018 | 2010-2018 | 2004- UDFA-CHN | Active | Chicago White Sox (MLB) | |
| Ji-Man Choi | 1B | Azl Mariners (Rk) Tacoma (AAA) | 6-1 | 195 | L-R | 1991-05-19 | 24 | Incheon,Korea | MLB | 2010-2018 | 2016-2018 | 2009- UDFA-SEA | Active | Tampa Bay Rays (MLB) | |
| Matt Clancy | P | Everett (A-) | 5-11 | 170 | L-L | 1994-04-01 | 21 | Norwood,New Jersey | A | 2015-2018 | - | 2015-13- 395-SEA | St. John's U. | Free Agent | - (MLB) |
| Ramire Cleto | P | Clinton (A) | 6-0 | 190 | R-R | 1993-04-04 | 22 | Villa Mella,Dom Rep | A | 2011-2016 | - | Free Agent | (MLB) | ||
| Trey Cochran-Gill | P | Bakersfield (A+) Jackson (AA) Tacoma (AAA) | 5-11 | 168 | R-R | 1992-12-10 | 22 | Tallassee,Alabama | AAA | 2014-2018 | - | 2014-17- 501-SEA | Auburn U. | Minors | Oakland Athletics (A+) |
| Danny Contreras | OF | DSL Mariners 2 (Rk) | 6-3 | 195 | L-L | 1998-05-21 | 17 | La Vega,Dom Rep | RK | 2015-2018 | - | 2014- UDFA-SEA | Minors | Seattle Mariners (Rk) | |
| Austin Cousino | OF | Azl Mariners (Rk) Clinton (A) | 5-10 | 178 | L-L | 1993-04-17 | 22 | Dublin,Ohio | AAA | 2012-2016 | - | 2014- 3- 80-SEA | Kentucky | Free Agent | (MLB) |
| Jordan Cowan | 2B-SS | Everett (A-) Bakersfield (A+) Jackson (AA) | 6-0 | 160 | L-R | 1995-04-13 | 20 | Covington,Washington | AA | 2013-2018 | - | 2013-37-1107-SEA | Minors | Seattle Mariners (A+) | |
| Augustus Craig | OF | Azl Mariners (Rk) | 6-2 | 220 | L-L | 1993-04-10 | 22 | - | A+ | 2015-2016 | - | 2015-30- 905-SEA | Columbia U. | Free Agent | (MLB) |
| Gus Craig | OF | Azl Mariners (Rk) | 6-2 | 210 | L-L | 1993-04-10 | 22 | Eugene,Oregon | RK | 2012-2015 | - | 2015-30- 905-SEA | Columbia U. | (MLB) | |
| Nelson Cruz | RF | Seattle (MLB) | 6-3 | 170 | R-R | 1980-07-01 | 34 | Monte Cristi,Dom Rep | MLB | 2001-2018 | 2005-2018 | 1998- UDFA-NYN | Active | Minnesota Twins (MLB) | |
| Saul Cuenca | P | DSL Mariners 2 (Rk) | 6-5 | 195 | R-R | 1998-03-22 | 17 | Barquisimeto,Venezuela | RK | 2015-2018 | - | (MLB) | |||
| Adonis De La Cruz | OF | DSL Mariners 2 (Rk) | 6-2 | 170 | R-R | 1994-12-20 | 20 | Santo Domingo,Dom Rep | A | 2013-2018 | - | Minors | New York Yankees (MLB) | ||
| Enyel De Los Santos | P | Azl Mariners (Rk) Everett (A-) | 6-3 | 170 | R-R | 1995-12-25 | 19 | San Pedro de Mac,Dom Rep | MLB | 2015-2018 | 2018-2018 | 2014- UDFA-SEA | Active | Philadelphia Phillies (MLB) | |
| Juan De Paula | P | DSL Mariners 2 (Rk) | 6-3 | 165 | R-R | 1997-09-22 | 17 | Santo Domingo,Dom Rep | A | 2015-2018 | - | 2014- UDFA-SEA | Minors | San Francisco Giants (A) | |
| Joe DeCarlo | 3B | Clinton (A) | 5-10 | 205 | R-R | 1993-09-13 | 21 | Glen Mills,Pennsylvania | AA | 2012-2018 | - | 2012- 2- 64-SEA | Minors | Seattle Mariners (AA) | |
| Scott Dececco | P | Bakersfield (A+) Jackson (AA) | 6-0 | 175 | R-L | 1991-05-08 | 24 | Cape May,New Jersey | AA | 2012-2015 | - | 2012-21- 641-SEA | South Carolina-Upstate | Free Agent | (MLB) |
| Edwin Diaz | P | Bakersfield (A+) Jackson (AA) | 6-2 | 160 | R-R | 1994-03-22 | 21 | Naguabo,Puerto Rico | MLB | 2012-2018 | 2016-2018 | 2012- 3- 98-SEA | Active | New York Mets (MLB) | |
| Anthony Dominguez | SS | DSL Mariners 2 (Rk) | 6-0 | 170 | R-R | 1996-06-06 | 19 | Santiago,Dom Rep | RK | 2013-2016 | - | (MLB) | |||
| Ronald Dominguez | P | Clinton (A) Bakersfield (A+) | 6-2 | 180 | R-R | 1994-01-13 | 21 | Villa Mella,Dom Rep | A+ | 2011-2017 | - | Free Agent | (MLB) | ||
| Mike Dowd | C | Azl Mariners (Rk) Jackson (AA) | 5-8 | 205 | R-R | 1990-04-10 | 25 | East Bridgewater,Massachusetts | AA | 2009-2016 | - | 2011-12- 363-SEA | Franklin Pierce U. | Free Agent | (MLB) |
| Roenis Elias | P | Tacoma (AAA) Seattle (MLB) | 6-2 | 178 | L-L | 1988-08-01 | 26 | Guantanamo,Cuba | MLB | 2011-2018 | 2014-2018 | 2011- UDFA-SEA | Active | Seattle Mariners (MLB) | |
| Frank Encarnacion | P | DSL Mariners 2 (Rk) | 6-3 | 195 | R-R | 1995-02-13 | 20 | Santo Domingo,Dom Rep | RK | 2014-2018 | - | Free Agent | - (MLB) | ||
| Ricky Eusebio | OF | Azl Mariners (Rk) | 5-10 | 175 | R-R | 1993-11-25 | 21 | Homestead,Florida | A+ | 2013-2017 | - | 2015-16- 485-SEA | Miami | Minors | Seattle Mariners (A+) |
| Danny Farquhar | P | Tacoma (AAA) Seattle (MLB) | 5-10 | 170 | R-R | 1987-02-17 | 28 | Pembroke Pines,Florida | MLB | 2008-2018 | 2011-2018 | 2008-10- 309-TOR | UL Lafayette | Minors | New York Yankees (MLB) |
| Jose Feliz | P | DSL Mariners 2 (Rk) | 6-0 | 170 | R-R | 1994-12-23 | 20 | San Cristobal,Dom Rep | RK | 2013-2016 | - | (MLB) | |||
| Alvaro Fernandez | P | DSL Mariners 2 (Rk) | 6-0 | 170 | R-R | 1996-09-01 | 18 | - | RK | 2015-2015 | - | (MLB) | |||
| Anthony Fernandez | P | Azl Mariners (Rk) Jackson (AA) | 6-4 | 180 | L-L | 1990-06-08 | 25 | Santiago,Dom Rep | AAA | 2009-2016 | - | Free Agent | (MLB) | ||
| Rafael Fernandez | SS | Azl Mariners (Rk) Everett (A-) Clinton (A) Jackson (AA) Tacoma (AAA) | 5-10 | 180 | B-R | 1994-04-21 | 21 | Carabobo,Venezuela | AAA | 2014-2016 | - | Free Agent | (MLB) | ||
| Arby Fields | RF-OF | Clinton (A) | 5-9 | 190 | B-R | 1991-06-25 | 24 | Alta Loma,California | A+ | 2010-2018 | - | 2011-27- 833-SDN | Northwestern U., Cypress Col, Louisiana St | Free Agent | (MLB) |
| Ramon Flores | OF | Tacoma (AAA) | 5-10 | 150 | L-L | 1992-03-26 | 23 | Barinas,Venezuela | MLB | 2009-2018 | 2015-2017 | 2008- UDFA-NYA | Free Agent | - (MLB) | |
| Rob Fonseca | 1B | Azl Mariners (Rk) | 6-2 | 205 | R-R | 1993-05-05 | 22 | Madison,New Jersey | RK | 2012-2015 | - | 2015-21- 635-SEA | Northeastern U. | Free Agent | (MLB) |
| Lachlan Fontaine | 3B | Azl Mariners (Rk) | 6-2 | 210 | L-R | 1995-08-27 | 19 | North Vancouver,BC | RK | 2013-2018 | - | 2013-13- 387-SEA | Free Agent | (MLB) | |
| Paul Fry | P | Bakersfield (A+) Jackson (AA) | 6-0 | 190 | L-L | 1992-07-26 | 22 | Waterford,Michigan | MLB | 2011-2018 | 2018-2018 | 2013-17- 507-SEA | St. Clair County CC | Active | Baltimore Orioles (MLB) |
| Charlie Furbush | P | Seattle (MLB) | 6-5 | 215 | L-L | 1986-04-11 | 29 | Portland,Maine | MLB | 2005-2016 | 2011-2015 | 2007- 4- 151-DET | Louisiana St, St. Joseph's Col Maine | Free Agent | (MLB) |
| Kevin Gadea | P | DSL Mariners 2 (Rk) | 6-5 | 188 | R-R | 1994-12-06 | 20 | Esteli,Nicaragua | A | 2014-2016 | - | 2012- UDFA-SEA | Minors | Tampa Bay Rays (A+) | |
| Julius Gaines | SS | Azl Mariners (Rk) | 5-10 | R-R | 1992-09-10 | 22 | Luella,Georgia | RK | 2012-2016 | - | 2015-33- 995-SEA | Florida International U. | Free Agent | (MLB) | |
| Oliver Garcia | P | Azl Mariners (Rk) | 6-2 | 205 | R-R | 1990-12-07 | 24 | Nizao,Dom Rep | A+ | 2010-2016 | - | Free Agent | (MLB) | ||
| Sam Gaviglio | P | Azl Mariners (Rk) Tacoma (AAA) | 6-2 | 180 | R-R | 1990-05-22 | 25 | Ashland,Oregon | MLB | 2011-2018 | 2017-2018 | 2011- 5- 170-SLN | Oregon St | Paternity | Toronto Blue Jays (MLB) |
| Justin Germano | P | Tacoma (AAA) | 6-2 | 190 | R-R | 1982-08-06 | 32 | Pasadena,California | MLB | 2000-2015 | 2004-2014 | 2000-13- 379-SDN | Free Agent | (MLB) | |
| Jimmy Gillheeney | P | Jackson (AA) Tacoma (AAA) | 6-1 | 199 | L-L | 1987-11-08 | 27 | Johnston,Rhode Island | AAA | 2009-2015 | - | 2009- 8- 233-SEA | North Carolina St | Free Agent | (MLB) |
| Darin Gillies | P | Everett (A-) | 6-4 | 202 | R-R | 1992-11-06 | 22 | Hollister,California | AAA | 2015-2018 | - | 2015-10- 305-SEA | Arizona St | Minors | Seattle Mariners (AA) |
| Luiz Gohara | P | Everett (A-) Clinton (A) | 6-3 | 210 | L-L | 1996-07-31 | 18 | Tupa,Brazil | MLB | 2013-2018 | 2017-2018 | 2012- UDFA-SEA | Active | Atlanta Braves (MLB) | |
| Ivan Gonzalez | SS | DSL Mariners (Rk) | 6-0 | 175 | R-R | 1995-10-28 | 19 | Bani,Dom Rep | A | 2013-2016 | - | Free Agent | (MLB) | ||
| Marvin Gorgas | P | Azl Mariners (Rk) | 5-9 | 185 | R-R | 1996-01-19 | 19 | Chicago,Illinois | AAA | 2014-2018 | - | 2014-13- 381-SEA | Minors | Seattle Mariners (A) | |
| Jesus Graterol | OF | DSL Mariners (Rk) | 6-0 | 145 | R-R | 1997-04-08 | 18 | Puerto Cabello,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Kevin Gregg | P | Tacoma (AAA) | 6-6 | 200 | R-R | 1978-06-20 | 37 | Corvallis,Oregon | MLB | 1996-2015 | 2003-2015 | 1996-15- 435-OAK | Free Agent | (MLB) | |
| Mayckol Guaipe | P | Tacoma (AAA) Seattle (MLB) | 6-3 | 175 | R-R | 1990-08-11 | 24 | Anzoategui,Venezuela | MLB | 2011-2017 | 2015-2016 | 2006- UDFA-SEA | Free Agent | (MLB) | |
| Gabby Guerrero | RF | Jackson (AA) | 6-3 | 190 | R-R | 1993-12-11 | 21 | Nizao,Dom Rep | MLB | 2011-2018 | 2018-2018 | 2011- UDFA-SEA | Minors | Miami Marlins (MLB) | |
| Franklin Gutierrez | RF-OF | Tacoma (AAA) Seattle (MLB) | 6-2 | 175 | R-R | 1983-02-21 | 32 | Caracas,Venezuela | MLB | 2001-2017 | 2005-2017 | 2000- UDFA-LAN | Free Agent | (MLB) | |
| Carlos Guzman | P | DSL Mariners (Rk) | 6-1 | 170 | R-L | 1997-01-28 | 18 | Santo Domingo,Dom Rep | RK | 2014-2018 | - | Minors | Seattle Mariners (Rk) | ||
| Conner Hale | IF | Everett (A-) | 6-2 | 191 | R-R | 1992-10-10 | 22 | Clearwater,Florida | A | 2012-2017 | - | 2015- 9- 275-SEA | Louisiana St, State Col Florida Manatee-Sarasota | Free Agent | (MLB) |
| J.A. Happ | P | Seattle (MLB) | 6-5 | 205 | L-L | 1982-10-19 | 32 | Spring Valley,Illinois | MLB | 2003-2018 | 2007-2018 | 2004- 3- 92-PHI | Northwestern U. | Active | New York Yankees (MLB) |
| Brock Hebert | SS-2B | Azl Mariners (Rk) Clinton (A) Bakersfield (A+) | 5-9 | 160 | R-R | 1991-05-11 | 24 | Bourg,Louisiana | AAA | 2010-2017 | - | 2012-14- 431-SEA | Southeastern Louisiana U. | Free Agent | (MLB) |
| Eugene Helder | SS | DSL Mariners (Rk) | 5-11 | 165 | R-R | 1996-02-26 | 19 | Oranjestad,Aruba | AAA | 2015-2018 | - | Minors | Seattle Mariners (AAA) | ||
| Jabari Henry | OF | Jackson (AA) | 6-0 | 198 | R-R | 1990-11-11 | 24 | Orlando,Florida | AA | 2010-2018 | - | 2012-18- 551-SEA | Florida International U. | Free Agent | (MLB) |
| Tyler Herb | P | Clinton (A) | 6-2 | 175 | R-R | 1992-04-28 | 23 | Lykens,Pennsylvania | AAA | 2014-2018 | - | 2014-29- 861-SEA | Coastal Carolina U. | Minors | San Francisco Giants (MLB) |
| Spencer Hermann | P | Everett (A-) | 6-4 | 235 | L-L | 1993-08-06 | 21 | Jacksonville,Florida | A+ | 2014-2017 | - | 2014-36-1071-SEA | Fisher Col, North Florida | Minors | Seattle Mariners (A+) |
| Anjul Hernandez | P | DSL Mariners 2 (Rk) | 6-2 | 192 | R-R | 1996-01-02 | 19 | Ocumare del Tuy,Venezuela | A- | 2015-2017 | - | Free Agent | (MLB) | ||
| Brayan Hernandez | OF | DSL Mariners 2 (Rk) | 6-2 | 175 | B-R | 1997-09-11 | 17 | Rio Chico,Venezuela | AAA | 2015-2018 | - | 2014- UDFA-SEA | Minors | Miami Marlins (A-) | |
| Carlos Hernandez | P | DSL Mariners (Rk) | 6-3 | 195 | R-R | 1996-02-08 | 19 | San Felix,Venezuela | A+ | 2015-2018 | - | Minors | Seattle Mariners (A+) | ||
| Felix Hernandez | P | Seattle (MLB) | 6-3 | 170 | R-R | 1986-04-08 | 29 | Valencia,Venezuela | MLB | 2003-2018 | 2005-2018 | 2002- UDFA-SEA | Active | Seattle Mariners (MLB) | |
| Moises Hernandez | P | Jackson (AA) | 6-1 | 170 | R-R | 1984-03-18 | 31 | Valencia,Venezuela | AAA | 2003-2015 | - | Free Agent | (MLB) | ||
| Albert Herrera | 2B | DSL Mariners 2 (Rk) | 5-11 | 160 | R-R | 1996-03-07 | 19 | Caja Seca,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Carlos Herrera | P | DSL Mariners (Rk) | 6-2 | 150 | R-R | 1997-10-26 | 17 | Esperanza,Dom Rep | A | 2015-2018 | - | 2014- UDFA-SEA | Minors | Milwaukee Brewers (A) | |
| John Hicks | C | Tacoma (AAA) Seattle (MLB) | 6-1 | 182 | R-R | 1989-08-31 | 25 | Sandy Hook,Virginia | MLB | 2009-2018 | 2015-2018 | 2011- 4- 123-SEA | Virginia | Active | Detroit Tigers (MLB) |
| Cameron Hobson | P | Azl Mariners (Rk) Jackson (AA) Tacoma (AAA) | 6-1 | 205 | L-L | 1989-04-10 | 26 | Crawfordsville,Indiana | AAA | 2011-2015 | - | 2011-11- 333-SEA | Dayton | Free Agent | (MLB) |
| Ryan Horstman | P | Azl Mariners (Rk) Everett (A-) Clinton (A) | 6-2 | 185 | L-L | 1992-07-20 | 22 | South hadley,Massachusetts | AA | 2013-2018 | - | 2013- 4- 117-SEA | St. John's U. | Free Agent | (MLB) |
| Danny Hultzen | P | Jackson (AA) | 6-2 | 195 | L-L | 1989-11-28 | 25 | Bethesda,Maryland | AAA | 2009-2018 | - | 2011- 1- 2-SEA | Virginia | Minors | Chicago Cubs (AAA) |
| Kyle Hunter | P | Azl Mariners (Rk) Jackson (AA) | 6-3 | 200 | R-L | 1989-06-18 | 26 | Richmond,Virginia | AAA | 2011-2017 | - | 2011-31- 933-SEA | Kansas St | Free Agent | (MLB) |
| Ryne Inman | P | Azl Mariners (Rk) | 6-5 | 215 | R-R | 1996-05-13 | 19 | Lawrenceville,Georgia | A | 2015-2018 | - | 2015-15- 455-SEA | Minors | Seattle Mariners (A) | |
| Hisashi Iwakuma | P | Everett (A-) Tacoma (AAA) Seattle (MLB) | 6-3 | 163 | R-R | 1981-04-12 | 34 | Tokyo,Japan | MLB | 2002-2018 | 2012-2017 | 2012- UDFA-SEA | Free Agent | - (MLB) | |
| Alex Jackson | C-OF | Everett (A-) Clinton (A) | 6-2 | 215 | R-R | 1995-12-25 | 19 | Escondido,California | AAA | 2014-2018 | - | 2014- 1- 6-SEA | Active | Atlanta Braves (MLB) | |
| Austin Jackson | CF | Tacoma (AAA) Seattle (MLB) | 6-1 | 185 | R-R | 1987-02-01 | 28 | Denton,Texas | MLB | 2005-2018 | 2010-2018 | 2005- 8- 259-NYA | Free Agent | (MLB) | |
| Drew Jackson | SS | Everett (A-) | 6-2 | 175 | R-R | 1993-07-28 | 21 | Orinda,California | AA | 2013-2018 | - | 2015- 5- 155-SEA | Stanford U. | Active | Baltimore Orioles (MLB) |
| Angel Jimenez | 3B | DSL Mariners 2 (Rk) Azl Mariners (Rk) | 6-1 | 180 | R-R | 1994-09-08 | 20 | Santo Domingo,Dom Rep | RK | 2012-2015 | - | Free Agent | (MLB) | ||
| Anthony Jimenez | OF | DSL Mariners (Rk) | 5-11 | 165 | R-R | 1995-10-21 | 19 | Caja Seca,Venezuela | A+ | 2015-2018 | - | Minors | Seattle Mariners (A+) | ||
| Luis Jimenez | P | DSL Mariners (Rk) | 6-0 | 178 | R-R | 1993-05-28 | 22 | Santiago,Dom Rep | RK | 2012-2015 | - | (MLB) | |||
| James Jones | OF | Azl Mariners (Rk) Tacoma (AAA) Seattle (MLB) | 6-4 | 195 | L-L | 1988-09-24 | 26 | Brooklyn,New York | MLB | 2007-2018 | 2014-2015 | 2009- 4- 113-SEA | Long Island U.-Brooklyn Campus | Free Agent | - (MLB) |
| P.J. Jones | C | Everett (A-) | 5-9 | 180 | R-R | 1993-02-25 | 22 | Vancouver,Washington | AAA | 2012-2016 | - | 2015-19- 575-SEA | Washington St | Free Agent | (MLB) |
| Luis Joseph | 2B | DSL Mariners 2 (Rk) | 5-9 | 160 | B-R | 1996-09-20 | 18 | Guaymate,Dom Rep | A+ | 2014-2018 | - | Minors | Seattle Mariners (Rk) | ||
| Dalton Kelly | OF | Azl Mariners (Rk) | 6-3 | 180 | L-L | 1994-08-04 | 20 | Redding,California | AA | 2013-2018 | - | 2015-38-1145-SEA | California-Santa Barbara | Minors | Tampa Bay Rays (AA) |
| Logan Kensing | P | Tacoma (AAA) Seattle (MLB) | 6-1 | 185 | R-R | 1982-07-03 | 32 | San Antonio,Texas | MLB | 2003-2018 | 2004-2016 | 2003- 2- 53-FLO | Texas A&M U. | Free Agent | (MLB) |
| Kody Kerski | P | Clinton (A) | 5-11 | 170 | R-R | 1992-04-18 | 23 | Waterbury,Connecticut | AAA | 2014-2017 | - | 2014- 8- 231-SEA | Sacred Heart U. | Free Agent | (MLB) |
| Mike Kickham | P | Tacoma (AAA) | 6-4 | 205 | L-L | 1988-12-12 | 26 | St. Louis,Missouri | MLB | 2010-2018 | 2013-2014 | 2011-33-1007-DET | Missouri St, Crowder Col | Minors | Miami Marlins (MLB) |
| Nick Kiel | P | Clinton (A) | 5-11 | 205 | R-L | 1992-11-30 | 22 | Mill Creek,Washington | A | 2014-2016 | - | 2014-18- 531-SEA | Bellevue CC | Free Agent | (MLB) |
| Andrew Kittredge | P | Jackson (AA) Tacoma (AAA) | 6-1 | 202 | R-R | 1990-03-17 | 25 | Spokane,Washington | MLB | 2009-2018 | 2017-2018 | 2008-45-1360-SEA | Washington | Minors | Tampa Bay Rays (MLB) |
| Patrick Kivlehan | 3B | Tacoma (AAA) | 6-2 | 210 | R-R | 1989-12-22 | 25 | West Nyack,New York | MLB | 2012-2018 | 2016-2018 | 2012- 4- 131-SEA | Rutgers U. | Minors | Pittsburgh Pirates (MLB) |
| Tyler Knigge | P | Jackson (AA) | 6-4 | 215 | R-R | 1988-10-27 | 26 | Lewiston,Idaho | AAA | 2010-2018 | - | 2010-12- 381-PHI | Lewis-Clark St | Free Agent | (MLB) |
| Erik Kratz | C | Tacoma (AAA) | 6-4 | 240 | R-R | 1980-06-15 | 35 | Telford,Pennsylvania | MLB | 1999-2018 | 2010-2018 | 2002-29- 866-TOR | Eastern Mennonite U. | Minors | Milwaukee Brewers (MLB) |
| Stephen Landazuri | P | Jackson (AA) Tacoma (AAA) | 6-0 | 175 | R-R | 1992-01-06 | 23 | Rialto,California | AAA | 2010-2017 | - | 2010-22- 672-SEA | Minors | Seattle Mariners (MLB) | |
| Leon Landry | OF | Jackson (AA) Tacoma (AAA) | 5-11 | 195 | R-R | 1989-09-20 | 25 | Baton Rouge,Louisiana | AAA | 2008-2017 | - | 2010- 3- 109-LAN | Louisiana St | Free Agent | (MLB) |
| Jordy Lara | 3B-1B | Jackson (AA) | 6-3 | 180 | R-R | 1991-05-21 | 24 | Bani,Dom Rep | AA | 2010-2016 | - | Free Agent | (MLB) | ||
| Alexdray Laya | 3B | DSL Mariners 2 (Rk) | 6-1 | 185 | R-R | 1995-10-06 | 19 | Maracay,Venezuela | RK | 2015-2015 | - | 2013- UDFA-SEA | (MLB) | ||
| Bryan Leal | OF | DSL Mariners 2 (Rk) | 6-0 | 165 | L-R | 1996-08-20 | 18 | Carupano,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Jose Leal | RF | Azl Mariners (Rk) | 6-3 | 215 | R-R | 1995-02-16 | 20 | Valle de la Pascua,Venezuela | A- | 2012-2016 | - | Free Agent | (MLB) | ||
| Dominic Leone | P | Tacoma (AAA) Seattle (MLB) | 5-10 | 175 | R-R | 1991-10-26 | 23 | Norwich,Connecticut | MLB | 2012-2018 | 2014-2018 | 2012-16- 491-SEA | Clemson U. | Active | St. Louis Cardinals (MLB) |
| Patrick Leyland | 1B | Clinton (A) Jackson (AA) | 6-2 | 198 | R-R | 1991-10-11 | 23 | Pittsburgh,Pennsylvania | AA | 2010-2015 | - | 2010- 8- 253-DET | Minors | Baltimore Orioles (AA) | |
| Luis Liberato | OF | Everett (A-) Clinton (A) Jackson (AA) | 6-1 | 175 | L-L | 1995-12-18 | 19 | La Canela,Dom Rep | AA | 2013-2018 | - | 2012- UDFA-SEA | Minors | Seattle Mariners (A+) | |
| Zack Littell | P | Clinton (A) | 6-3 | 190 | R-R | 1995-10-05 | 19 | Mebane,North Carolina | MLB | 2013-2018 | 2018-2018 | 2013-11- 327-SEA | Active | Minnesota Twins (MLB) | |
| Marcus Littlewood | C | Bakersfield (A+) Jackson (AA) | 6-3 | 198 | B-R | 1992-03-18 | 23 | St. George,Utah | AAA | 2011-2018 | - | 2010- 2- 67-SEA | Free Agent | - (MLB) | |
| Timmy Lopes | 2B | Bakersfield (A+) | 5-11 | 180 | R-R | 1994-06-24 | 21 | Huntington Beach,California | AAA | 2012-2018 | - | 2012- 6- 191-SEA | Minors | Seattle Mariners (MLB) | |
| Pablo Lopez | P | Azl Mariners (Rk) | 6-3 | 200 | R-R | 1996-03-07 | 19 | Cabimas,Venezuela | MLB | 2015-2018 | 2018-2018 | 2012- UDFA-SEA | Active | Miami Marlins (MLB) | |
| Robinson Lopez | P | DSL Mariners (Rk) | 6-1 | 175 | R-R | 1996-06-02 | 19 | Valencia,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Mark Lowe | P | Tacoma (AAA) Seattle (MLB) | 6-4 | 180 | R-R | 1983-06-07 | 32 | Houston,Texas | MLB | 2004-2017 | 2006-2016 | 2004- 5- 153-SEA | Texas-Arlington | Free Agent | (MLB) |
| Lucas Luetge | P | Azl Mariners (Rk) Tacoma (AAA) Seattle (MLB) | 6-3 | 198 | L-L | 1987-02-24 | 28 | Brenham,Texas | MLB | 2008-2017 | 2012-2015 | 2008-21- 638-MIL | Rice U., San Jacinto Col | Free Agent | (MLB) |
| Chantz Mack | OF | Clinton (A) Bakersfield (A+) | 5-11 | 205 | R-L | 1991-05-04 | 24 | Homestead,Florida | AAA | 2010-2017 | - | 2013-29- 867-SEA | Miami | Free Agent | (MLB) |
| Romulo Manzueta | P | DSL Mariners (Rk) | 6-2 | 160 | L-L | 1995-10-09 | 19 | Santo Domingo,Dom Rep | RK | 2013-2015 | - | (MLB) | |||
| Chris Mariscal | SS | Clinton (A) | 5-10 | 170 | R-R | 1993-04-26 | 22 | Fresno,California | AA | 2012-2018 | - | 2014-14- 411-SEA | Fresno St | Minors | Seattle Mariners (AA) |
| Tyler Marlette | C | Bakersfield (A+) Jackson (AA) | 5-11 | 195 | R-R | 1993-01-23 | 22 | Oviedo,Florida | AA | 2011-2018 | - | 2011- 5- 153-SEA | Free Agent | - (MLB) | |
| Wladimir Marruffo | P | DSL Mariners (Rk) | 6-0 | 173 | R-R | 1993-05-29 | 22 | Nueva Esparta,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Ketel Marte | SS | Azl Mariners (Rk) Jackson (AA) Tacoma (AAA) Seattle (MLB) | 6-1 | 180 | B-R | 1993-10-12 | 21 | Nizao,Dom Rep | MLB | 2011-2018 | 2015-2018 | 2010- UDFA-SEA | Active | Arizona Diamondbacks (MLB) | |
| Adam Martin | C | Azl Mariners (Rk) Everett (A-) Clinton (A) | 6-3 | 215 | R-R | 1991-12-07 | 23 | Marietta,Georgia | A | 2011-2017 | - | 2014-10- 291-SEA | Western Carolina U. | Free Agent | (MLB) |
| Edwin Martinez | P | DSL Mariners (Rk) | 6-6 | 240 | R-R | 1995-07-31 | 19 | Santo Domingo,Dom Rep | RK | 2014-2018 | - | Free Agent | - (MLB) | ||
| Hersin Martinez | OF | Azl Mariners (Rk) | 6-5 | 220 | R-R | 1995-02-27 | 20 | Santo Domingo,Dom Rep | RK | 2012-2015 | - | 2012- UDFA-SEA | Free Agent | (MLB) | |
| Will Mathis | P | Bakersfield (A+) | 6-3 | 180 | L-L | 1990-08-18 | 24 | Carlsbad,New Mexico | A+ | 2013-2018 | - | 2013-25- 747-SEA | New Mexico, Georgia Perimeter Col | Free Agent | (MLB) |
| Jeffeson Medina | P | Clinton (A) | 6-2 | 184 | R-R | 1994-05-31 | 21 | Zulia,Venezuela | A+ | 2013-2018 | - | Minors | Texas Rangers (MLB) | ||
| Yoervis Medina | P | Tacoma (AAA) Seattle (MLB) | 6-3 | 210 | R-R | 1988-07-27 | 26 | Puerto Cabello,Venezuela | MLB | 2010-2016 | 2013-2015 | 2005- UDFA-SEA | Free Agent | (MLB) | |
| Erick Mejia | SS | Azl Mariners (Rk) Everett (A-) Clinton (A) Tacoma (AAA) | 5-11 | 155 | B-R | 1994-11-09 | 20 | Villa Mella,Dom Rep | AAA | 2012-2018 | - | Minors | Kansas City Royals (AA) | ||
| Brad Miller | SS | Seattle (MLB) | 6-1 | 185 | L-R | 1989-10-18 | 25 | Orlando,Florida | MLB | 2008-2018 | 2013-2018 | 2011- 2- 62-SEA | Clemson U. | Free Agent | (MLB) |
| Ian Miller | OF | Bakersfield (A+) Jackson (AA) | 6-0 | 175 | L-L | 1992-02-21 | 23 | Downington,Pennsylvania | AAA | 2011-2018 | - | 2013-14- 417-SEA | Wagner Col | Minors | Seattle Mariners (AAA) |
| Peter Miller | P | Clinton (A) | 6-1 | 185 | R-R | 1992-04-27 | 23 | Tampa,Florida | A | 2011-2015 | - | 2014- 9- 261-SEA | Florida St | Retired | (MLB) |
| Trevor Miller | P | Jackson (AA) | 6-3 | 190 | R-R | 1991-06-13 | 24 | Camp,California | AAA | 2011-2015 | - | 2011-40-1203-SEA | San Joaquin Delta Col | Free Agent | (MLB) |
| Yohailys Millord | P | Azl Mariners (Rk) | 6-2 | 180 | R-R | 1993-12-04 | 21 | El Limon,Dom Rep | RK | 2013-2017 | - | Free Agent | (MLB) | ||
| Carlos Misell | P | Bakersfield (A+) | 6-1 | 165 | R-R | 1992-04-25 | 23 | Ocumare del Tuy,Venezuela | A+ | 2013-2017 | - | Chipola Col | Free Agent | (MLB) | |
| Anthony Misiewicz | P | Everett (A-) | 6-1 | 186 | R-L | 1994-11-01 | 20 | Chesterfield,Michigan | AA | 2015-2018 | - | 2015-18- 545-SEA | Michigan St | Minors | Seattle Mariners (AA) |
| Daniel Missaki | P | Clinton (A) | 6-0 | 170 | R-R | 1996-04-09 | 19 | Sao Paolo,Brazil | A | 2013-2015 | - | 2013- UDFA-SEA | Minors | Milwaukee Brewers (Rk) | |
| Cody Mobley | P | Azl Mariners (Rk) | 6-3 | 190 | R-R | 1996-09-23 | 18 | Mount Vernon,Indiana | A- | 2015-2018 | - | 2015- 8- 245-SEA | Minors | Seattle Mariners (A-) | |
| Jesus Montero | C | Tacoma (AAA) Seattle (MLB) | 6-4 | 225 | R-R | 1989-11-29 | 25 | Guacara,Venezuela | MLB | 2007-2017 | 2011-2015 | 2006- UDFA-NYA | Free Agent | (MLB) | |
| Mike Montgomery | P | Tacoma (AAA) Seattle (MLB) | 6-5 | 180 | L-L | 1989-07-01 | 25 | Valencia,California | MLB | 2008-2018 | 2015-2018 | 2008- 1- 36-KCA | Active | Chicago Cubs (MLB) | |
| Geoandry Montilla | 1B | DSL Mariners (Rk) | 6-0 | 165 | R-R | 1996-05-14 | 19 | Maracaibo,Venezuela | A- | 2015-2018 | - | Minors | Seattle Mariners (A-) | ||
| Andrew Moore | P | Everett (A-) | 5-11 | 180 | R-R | 1994-06-02 | 21 | Eugene,Oregon | MLB | 2015-2018 | 2017-2017 | 2015- 2- 72-SEA | Oregon St | Active | Tampa Bay Rays (MLB) |
| Estarlyn Morales | OF | Clinton (A) Bakersfield (A+) | 6-3 | 180 | R-R | 1992-10-28 | 22 | Santo Domingo,Dom Rep | A+ | 2010-2015 | - | Free Agent | (MLB) | ||
| Jhombeyker Morales | SS | Azl Mariners (Rk) Clinton (A) Tacoma (AAA) | 6-0 | 170 | R-R | 1994-07-17 | 20 | Aragua,Venezuela | AAA | 2014-2018 | - | Free Agent | - (MLB) | ||
| Osmer Morales | P | Clinton (A) | 6-3 | 196 | R-R | 1992-10-30 | 22 | Villa de Cura,Venezuela | MLB | 2014-2018 | 2018-2018 | Free Agent | - (MLB) | ||
| Brian Moran | P | Bakersfield (A+) Jackson (AA) | 6-3 | 188 | L-L | 1988-09-30 | 26 | Rye,New York | AAA | 2009-2018 | - | 2009- 7- 203-SEA | North Carolina | Minors | Miami Marlins (MLB) |
| Julio Morban | OF | Jackson (AA) Tacoma (AAA) | 6-1 | 190 | L-L | 1992-02-13 | 23 | San Cristobal,Dom Rep | AAA | 2009-2015 | - | Free Agent | (MLB) | ||
| Gareth Morgan | OF | Azl Mariners (Rk) | 6-4 | 220 | R-R | 1996-04-12 | 19 | Toronto,Ontario | A+ | 2014-2018 | - | 2014- 2- 74-SEA | Minors | Seattle Mariners (A+) | |
| Ramon Morla | 3B | Azl Mariners (Rk) Bakersfield (A+) | 6-1 | 175 | R-R | 1989-11-20 | 25 | San Pedro de Mac,Dom Rep | AA | 2009-2016 | - | Free Agent | (MLB) | ||
| Logan Morrison | 1B | Seattle (MLB) | 6-4 | 245 | L-L | 1987-08-25 | 27 | Kansas City,Missouri | MLB | 2006-2018 | 2010-2018 | 2005-22- 666-FLO | Maple Woods CC | Free Agent | (MLB) |
| Ismerling Mota | C | DSL Mariners (Rk) | 6-1 | 185 | R-R | 1997-09-02 | 17 | Cambita Garabito,Dom Rep | RK | 2015-2018 | - | 2014- UDFA-SEA | Minors | Seattle Mariners (Rk) | |
| Jay Muhammad | P | Azl Mariners (Rk) | 6-2 | 195 | R-R | 1994-11-14 | 20 | Somerset,New Jersey | A+ | 2014-2018 | - | 2014-11- 321-SEA | Free Agent | - (MLB) | |
| Oberto Munoz | C | DSL Mariners (Rk) | 6-0 | 170 | R-R | 1997-02-18 | 18 | Maracaibo,Venezuela | RK | 2015-2018 | - | Free Agent | - (MLB) | ||
| Nick Neidert | P | Azl Mariners (Rk) | 6-1 | 180 | R-R | 1996-11-20 | 18 | Suwanee,Georgia | AA | 2015-2018 | - | 2015- 2- 60-SEA | Minors | Miami Marlins (MLB) | |
| Ljay Newsome | P | Azl Mariners (Rk) | 5-11 | 210 | R-R | 1996-11-08 | 18 | La Plata,Maryland | AAA | 2015-2018 | - | 2015-26- 785-SEA | Minors | Seattle Mariners (A+) | |
| Arturo Nieto | C | Everett (A-) | 6-2 | 195 | R-R | 1992-12-09 | 22 | Maracay,Venezuela | A+ | 2013-2017 | - | Minors | San Diego Padres (MLB) | ||
| Vinny Nittoli | P | Azl Mariners (Rk) | 6-1 | 205 | R-R | 1990-11-11 | 24 | Tempe,Arizona | A+ | 2011-2018 | - | 2014-25- 741-SEA | Xavier U. | Minors | Seattle Mariners (MLB) |
| Vidal Nuno | P | Tacoma (AAA) Seattle (MLB) | 5-11 | 195 | L-L | 1987-07-26 | 27 | National City,California | MLB | 2009-2018 | 2013-2018 | 2009-48-1445-CLE | Baker U. | Minors | Washington Nationals (MLB) |
| Shawn O'Malley | SS | Everett (A-) Tacoma (AAA) Seattle (MLB) | 5-10 | 155 | B-R | 1987-12-28 | 27 | Richland,Washington | MLB | 2006-2018 | 2014-2016 | 2006- 5- 139-TBA | Free Agent | - (MLB) | |
| Tyler O'Neill | OF | Bakersfield (A+) | 5-11 | 205 | R-R | 1995-06-22 | 20 | Maple Ridge,BC | MLB | 2013-2018 | 2018-2018 | 2013- 3- 85-SEA | Active | St. Louis Cardinals (MLB) | |
| Edgar Olmos | P | Tacoma (AAA) Seattle (MLB) | 6-5 | 180 | L-L | 1990-04-12 | 25 | Van Nuys,California | MLB | 2008-2017 | 2013-2015 | 2008- 3- 83-FLO | International | (MLB) | |
| Tyler Olson | P | Tacoma (AAA) Seattle (MLB) | 6-3 | 180 | R-L | 1989-10-02 | 25 | Spokane,Washington | MLB | 2013-2018 | 2015-2018 | 2013- 7- 207-SEA | Gonzaga U. | Active | Cleveland Indians (MLB) |
| Jio Orozco | P | Azl Mariners (Rk) | 6-1 | 208 | R-R | 1997-08-15 | 17 | Tucson,Arizona | A | 2015-2018 | - | 2015-14- 425-SEA | Minors | New York Yankees (A) | |
| Paolo Padovani | P | DSL Mariners (Rk) | 6-2 | 175 | R-R | 1994-08-22 | 20 | San Felix,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Emilio Pagan | P | Bakersfield (A+) | 6-2 | 180 | L-R | 1991-05-07 | 24 | Simpsonville,South Carolina | MLB | 2010-2018 | 2017-2018 | 2013-10- 297-SEA | Gardner-Webb U., Belmont Abbey Col | Active | Tampa Bay Rays (MLB) |
| Dan Paolini | 1B-OF | Jackson (AA) Tacoma (AAA) | 6-1 | 180 | R-R | 1989-10-11 | 25 | Stratford,Connecticut | AAA | 2009-2016 | - | 2011-10- 303-SEA | Siena Col | Free Agent | (MLB) |
| James Paxton | P | Tacoma (AAA) Seattle (MLB) | 6-3 | 200 | L-L | 1988-11-06 | 26 | Richmond,BC | MLB | 2010-2018 | 2013-2018 | 2010- 4- 132-SEA | Kentucky | Active | New York Yankees (MLB) |
| Raul Pedie | P | DSL Mariners 2 (Rk) | 6-0 | 175 | R-R | 1992-08-14 | 22 | Villa Mella,Dom Rep | RK | 2012-2015 | - | (MLB) | |||
| Joe Peeler | P | Azl Mariners (Rk) | 6-4 | 175 | R-R | 1996-12-02 | 18 | Rockwell,North Carolina | RK | 2015-2016 | - | 2015-25- 755-SEA | Mount Olive Col | Free Agent | (MLB) |
| Martin Peguero | SS-3B | Clinton (A) Bakersfield (A+) | 6-1 | 185 | R-R | 1993-11-03 | 21 | Bani,Dom Rep | A+ | 2011-2015 | - | Free Agent | (MLB) | ||
| Onil Pena | C | DSL Mariners 2 (Rk) | 6-0 | 180 | R-R | 1996-11-06 | 18 | Salcedo,Dom Rep | A | 2014-2018 | - | 2013- UDFA-SEA | Minors | Seattle Mariners (A) | |
| Freddy Peralta | P | Azl Mariners (Rk) | 5-11 | 175 | R-R | 1996-06-04 | 19 | Moca,Dom Rep | MLB | 2013-2018 | 2018-2018 | 2013- UDFA-SEA | Active | Milwaukee Brewers (MLB) | |
| Taylor Perez | SS | Azl Mariners (Rk) | 5-9 | 170 | R-R | 1993-12-26 | 21 | St. Petersburg,Florida | RK | 2013-2016 | - | 2015-28- 845-SEA | Saint Leo U. | Free Agent | (MLB) |
| Ulises Perez | P | Azl Mariners (Rk) | 6-3 | 160 | R-R | 1997-07-14 | 17 | Valencia,Venezuela | A- | 2014-2018 | - | 2013- UDFA-SEA | Minors | Seattle Mariners (A-) | |
| Yeison Perez | C | DSL Mariners (Rk) | 6-0 | 185 | R-R | 1996-04-09 | 19 | Santo Domingo,Dom Rep | RK | 2014-2018 | - | Minors | Minnesota Twins (Rk) | ||
| D.J. Peterson | 3B | Jackson (AA) Tacoma (AAA) | 6-1 | 205 | R-R | 1991-12-31 | 23 | Gilbert,Arizona | AAA | 2011-2018 | - | 2013- 1- 12-SEA | New Mexico | Minors | Chicago White Sox (MLB) |
| Patrick Peterson | P | Clinton (A) | 6-3 | 190 | R-L | 1993-03-08 | 22 | Bear,Delaware | A | 2014-2017 | - | 2014-23- 681-SEA | Temple U., North Carolina St | Free Agent | (MLB) |
| Kyle Petty | 1B | Bakersfield (A+) | 6-5 | 220 | R-R | 1991-03-01 | 24 | Stewartsville,New Jersey | AA | 2010-2017 | - | 2013-23- 687-SEA | California Pennsylvania | Free Agent | (MLB) |
| Rohn Pierce | P | Everett (A-) Clinton (A) Bakersfield (A+) | 6-2 | 212 | R-R | 1993-01-21 | 22 | Lockport,New York | A+ | 2014-2017 | - | 2014-19- 561-SEA | Canisius Col | Free Agent | (MLB) |
| Tyler Pike | P | Bakersfield (A+) Jackson (AA) | 6-0 | 180 | L-L | 1994-01-26 | 21 | Winter Haven,Florida | AA | 2012-2018 | - | 2012- 3- 126-SEA | Free Agent | - (MLB) | |
| Guillermo Pimentel | OF | Bakersfield (A+) Jackson (AA) | 6-1 | 190 | R-R | 1992-10-05 | 22 | Santo Domingo,Dom Rep | AA | 2009-2015 | - | Free Agent | (MLB) | ||
| Andres Pina | P | DSL Mariners (Rk) | 6-3 | 200 | R-R | 1995-01-16 | 20 | Guacara,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Rafael Pineda | P | Bakersfield (A+) Tacoma (AAA) | 6-6 | 210 | R-R | 1991-02-03 | 24 | Salem,Oregon | AAA | 2013-2017 | - | 2013-30- 897-SEA | Texas A&M U. | Minors | Seattle Mariners (MLB) |
| Joe Pistorese | P | Everett (A-) | 6-1 | 165 | L-L | 1992-10-15 | 22 | Kalispell,Montana | AA | 2015-2018 | - | 2015-17- 515-SEA | Washington St | Free Agent | - (MLB) |
| Dario Pizzano | OF | Jackson (AA) | 5-11 | 190 | L-R | 1991-04-25 | 24 | Boston,Massachusetts | AAA | 2010-2018 | - | 2012-15- 461-SEA | Columbia U. | Free Agent | - (MLB) |
| Jordan Pries | P | Tacoma (AAA) | 6-1 | 185 | R-R | 1990-01-27 | 25 | Alameda,California | AAA | 2011-2016 | - | 2011-30- 903-SEA | Stanford U. | Free Agent | (MLB) |
| Carlos Quentin | LF | Tacoma (AAA) | 6-2 | 215 | R-R | 1982-08-28 | 32 | Bellflower,California | MLB | 2001-2017 | 2006-2014 | 2003- 1- 29-ARI | Stanford U. | Free Agent | (MLB) |
| Johan Quevedo | C | Everett (A-) | 6-1 | 212 | B-R | 1993-11-06 | 21 | Santa Barbara,Venezuela | A+ | 2014-2018 | - | Free Agent | - (MLB) | ||
| J.C. Ramirez | P | Tacoma (AAA) Seattle (MLB) | 6-3 | 175 | R-R | 1988-08-16 | 26 | Managua,Nicaragua | MLB | 2007-2018 | 2013-2018 | 2005- UDFA-SEA | Active | Los Angeles Angels (MLB) | |
| Jose Ramirez | P | Tacoma (AAA) Seattle (MLB) | 6-1 | 155 | R-R | 1990-01-21 | 25 | Yaguate,Dom Rep | MLB | 2009-2018 | 2014-2018 | 2007- UDFA-NYA | Free Agent | - (MLB) | |
| Rob Rasmussen | P | Tacoma (AAA) Seattle (MLB) | 5-11 | 155 | R-L | 1989-04-02 | 26 | Arcadia,California | MLB | 2010-2015 | 2014-2015 | 2010- 2- 73-FLO | UCLA | Retired | (MLB) |
| Lane Ratliff | P | Everett (A-) | 6-3 | 185 | L-L | 1995-03-22 | 20 | Purvis,Mississippi | AAA | 2014-2018 | - | 2014- 6- 171-SEA | Jones County Junior Col | Minors | Arizona Diamondbacks (A) |
| Jack Reinheimer | SS | Jackson (AA) | 6-0 | 165 | R-R | 1992-07-19 | 22 | Charlotte,North Carolina | MLB | 2011-2018 | 2017-2018 | 2013- 5- 147-SEA | East Carolina U. | Minors | Baltimore Orioles (MLB) |
| Luis Rengifo | 2B | DSL Mariners 2 (Rk) | 5-10 | 165 | B-R | 1997-02-26 | 18 | Naguanagua,Venezuela | AAA | 2015-2018 | - | 2013- UDFA-SEA | Active | Los Angeles Angels (MLB) | |
| Ricardo Reyes | P | DSL Mariners 2 (Rk) | 6-7 | 198 | R-R | 1993-10-17 | 21 | Santo Domingo,Dom Rep | RK | 2014-2015 | - | (MLB) | |||
| Burt Reynolds | SS | Clinton (A) Bakersfield (A+) Jackson (AA) | 6-1 | 190 | R-R | 1988-09-13 | 26 | San Pedro de Mac,Dom Rep | AA | 2008-2018 | - | 2006-30- 901-WAS | Free Agent | (MLB) | |
| Michael Rivera | P | Azl Mariners (Rk) | 6-3 | 220 | R-R | 1997-06-19 | 18 | Perth Amboy,New Jersey | AAA | 2015-2017 | - | 2015-27- 815-SEA | Free Agent | (MLB) | |
| Carlos Rivero | 3B | Tacoma (AAA) | 6-3 | 198 | R-R | 1988-05-20 | 27 | Barquisimeto,Venezuela | MLB | 2006-2017 | 2014-2014 | 2005- UDFA-CLE | Free Agent | (MLB) | |
| Fernando Rodney | P | Seattle (MLB) | 5-11 | 170 | R-R | 1981-03-17 | 34 | Samana,Dom Rep | MLB | 1999-2018 | 2002-2018 | 1997- UDFA-DET | Active | Oakland Athletics (MLB) | |
| Aderlin Rodriguez | 3B | Jackson (AA) | 6-3 | 210 | R-R | 1991-11-18 | 23 | Santo Domingo,Dom Rep | AA | 2009-2018 | - | Minors | San Diego Padres (MLB) | ||
| Carlos Rodriguez | P | DSL Mariners 2 (Rk) | 6-0 | 190 | R-R | 1995-05-23 | 20 | Anzoategui,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Brayan Rojas | OF | DSL Mariners (Rk) | 6-2 | 180 | R-R | 1995-01-05 | 20 | Villa Altagracia,Dom Rep | RK | 2014-2015 | - | (MLB) | |||
| David Rollins | P | Tacoma (AAA) Seattle (MLB) | 5-11 | 175 | L-L | 1989-12-21 | 25 | Carthage,Texas | MLB | 2011-2018 | 2015-2016 | 2011-24- 739-TOR | San Jacinto Col | Free Agent | - (MLB) |
| Stefen Romero | OF | Tacoma (AAA) Seattle (MLB) | 6-3 | 225 | R-R | 1988-10-17 | 26 | Tucson,Arizona | MLB | 2008-2017 | 2014-2016 | 2010-12- 372-SEA | Oregon St, Pima CC | International | (MLB) |
| Jose Rosa | C | DSL Mariners 2 (Rk) | 6-0 | 175 | R-R | 1994-03-07 | 21 | Villa Mella,Dom Rep | RK | 2012-2015 | - | (MLB) | |||
| Joseph Rosa | SS | DSL Mariners (Rk) | 5-10 | 165 | B-R | 1997-03-06 | 18 | New York,New York | AAA | 2015-2018 | - | Minors | Seattle Mariners (A) | ||
| Ronald Rosario | OF | DSL Mariners 2 (Rk) | 6-2 | 165 | L-L | 1997-02-08 | 18 | Villa Jaragua,Dom Rep | A- | 2014-2018 | - | 2013- UDFA-SEA | Minors | Seattle Mariners (Rk) | |
| Justin Ruggiano | CF | Tacoma (AAA) Seattle (MLB) | 6-2 | 205 | R-R | 1982-04-12 | 33 | Austin,Texas | MLB | 2003-2017 | 2007-2017 | 2004-25- 748-LAN | Texas A&M U., Blinn Col | Free Agent | (MLB) |
| Edward Salinas | P | DSL Mariners (Rk) | 6-2 | 175 | R-R | 1996-01-03 | 19 | San Sebastian,Venezuela | RK | 2015-2016 | - | (MLB) | |||
| Adrian Sampson | P | Tacoma (AAA) | 6-3 | 200 | R-R | 1991-10-07 | 23 | Issaquah,Washington | MLB | 2012-2018 | 2016-2018 | 2012- 5- 166-PIT | Bellevue CC | Minors | Texas Rangers (MLB) |
| Jose Sandoval | OF | DSL Mariners (Rk) | 6-2 | 195 | R-R | 1996-10-23 | 18 | La Guaira,Venezuela | RK | 2015-2017 | - | Minors | Seattle Mariners (Rk) | ||
| Jose Santiago | P | Everett (A-) | 6-1 | 190 | R-R | 1994-03-01 | 21 | Santo Domingo,Dom Rep | A+ | 2013-2017 | - | 2013- UDFA-SEA | Free Agent | (MLB) | |
| Joe Saunders | P | Tacoma (AAA) | 6-3 | 195 | L-L | 1981-06-16 | 34 | Fairfax,Virginia | MLB | 2002-2015 | 2005-2014 | 2002- 1- 12-ANA | Virginia Tech | Free Agent | (MLB) |
| Kyle Schepel | P | Clinton (A) Bakersfield (A+) Tacoma (AAA) | 6-1 | 235 | R-R | 1990-08-07 | 24 | Grand Rapids,Michigan | AAA | 2011-2018 | - | Grand Valley St | Free Agent | (MLB) | |
| Lukas Schiraldi | P | Clinton (A) | 6-4 | 197 | R-R | 1993-07-25 | 21 | Austin,Texas | AA | 2014-2018 | - | 2014-15- 441-SEA | Navarro Col, Texas | Minors | Miami Marlins (AA) |
| Troy Scott | P | Everett (A-) Clinton (A) | 6-3 | 200 | R-R | 1993-11-17 | 21 | Lake Elsinore,California | A | 2013-2015 | - | 2013-18- 537-SEA | Riverside CC | Free Agent | (MLB) |
| Justin Seager | 1B-3B | Bakersfield (A+) | 6-2 | 199 | R-R | 1992-05-15 | 23 | Kannapolis,North Carolina | AA | 2011-2017 | - | 2013-12- 357-SEA | UNC Charlotte | Minors | Seattle Mariners (AA) |
| Kyle Seager | 3B | Seattle (MLB) | 6-1 | 194 | L-R | 1987-11-03 | 27 | Charlotte,North Carolina | MLB | 2007-2018 | 2011-2018 | 2009- 3- 82-SEA | North Carolina | Active | Seattle Mariners (MLB) |
| Robert Severino | P | DSL Mariners 2 (Rk) | 6-2 | 185 | L-R | 1994-02-14 | 21 | Santiago,Dom Rep | RK | 2014-2016 | - | (MLB) | |||
| Zach Shank | 2B-SS | Jackson (AA) Tacoma (AAA) | 6-1 | 190 | R-R | 1991-01-06 | 24 | York,Pennsylvania | AAA | 2010-2018 | - | 2013-28- 837-SEA | Marist Col | Retired | - (MLB) |
| Jordan Shipers | P | Jackson (AA) | 5-11 | 165 | R-L | 1991-06-27 | 24 | Bethany,Missouri | AA | 2011-2015 | - | 2010-16- 492-SEA | Retired | (MLB) | |
| Dylan Silva | P | Everett (A-) | 6-1 | 215 | L-L | 1993-12-27 | 21 | Lake Worth,Florida | A | 2015-2016 | - | 2015-11- 335-SEA | Florida St | Free Agent | (MLB) |
| Corey Simpson | RF-OF | Everett (A-) | 6-2 | 210 | R-R | 1993-12-08 | 21 | Sweeny,Texas | AAA | 2013-2015 | - | 2013- 6- 177-SEA | Minors | Seattle Mariners (MLB) | |
| Misael Siverio | P | Jackson (AA) | 5-9 | 210 | L-L | 1989-06-12 | 26 | Villa Clara,Cuba | AAA | 2015-2017 | - | Free Agent | (MLB) | ||
| Carson Smith | P | Seattle (MLB) | 6-5 | 215 | R-R | 1989-10-19 | 25 | Dallas,Texas | MLB | 2012-2018 | 2014-2018 | 2011- 8- 243-SEA | Texas St, Grayson County Col | Minors | Boston Red Sox (MLB) |
| Seth Smith | DH-LF | Seattle (MLB) | 6-3 | 215 | L-L | 1982-09-30 | 32 | Beverly Hills,California | MLB | 2002-2017 | 2007-2017 | 2004- 2- 50-COL | Mississippi | Free Agent | (MLB) |
| Tyler Smith | SS | Jackson (AA) | 6-0 | 180 | R-R | 1991-07-01 | 23 | Long Beach,California | MLB | 2010-2018 | 2017-2017 | 2013- 8- 237-SEA | Oregon St | Free Agent | - (MLB) |
| Forrest Snow | P | Tacoma (AAA) | 6-6 | 210 | R-R | 1988-12-30 | 26 | Seattle,Washington | AAA | 2010-2018 | - | 2010-36-1092-SEA | Washington | Minors | Los Angeles Angels (MLB) |
| Joey Strain | P | Azl Mariners (Rk) Everett (A-) | 6-1 | 175 | R-R | 1994-01-17 | 21 | Annapolis,Maryland | A+ | 2015-2017 | - | 2015-22- 665-SEA | Winthrop U. | Free Agent | (MLB) |
| Michael Suarez | P | DSL Mariners (Rk) | 6-2 | 180 | L-L | 1995-03-21 | 20 | San Felipe,Venezuela | A- | 2015-2018 | - | Minors | Seattle Mariners (Rk) | ||
| Jesus Sucre | C | Tacoma (AAA) Seattle (MLB) | 6-0 | 200 | R-R | 1988-04-30 | 27 | Cumana,Venezuela | MLB | 2007-2018 | 2013-2018 | 2005- UDFA-ATL | Minors | Baltimore Orioles (MLB) | |
| Carlton Tanabe | C | Bakersfield (A+) Jackson (AA) | 6-0 | 190 | R-R | 1991-10-28 | 23 | Honolulu,Hawaii | AA | 2009-2016 | - | 2009-24- 713-SEA | Free Agent | (MLB) | |
| Andy Taveras | P | DSL Mariners 2 (Rk) | 6-2 | 185 | R-R | 1996-04-30 | 19 | Santiago,Dom Rep | RK | 2015-2016 | - | (MLB) | |||
| Chris Taylor | SS | Tacoma (AAA) Seattle (MLB) | 6-0 | 170 | R-R | 1990-08-29 | 24 | Virginia Beach,Virginia | MLB | 2010-2018 | 2014-2018 | 2012- 5- 161-SEA | Virginia | Active | Los Angeles Dodgers (MLB) |
| Logan Taylor | IF | Everett (A-) | 6-1 | 200 | R-R | 1993-09-22 | 21 | Houston,Texas | AAA | 2013-2018 | - | 2015-12- 365-SEA | Texas A&M U. | Minors | Seattle Mariners (AA) |
| Wayne Taylor | C | Clinton (A) | 6-1 | 205 | L-R | 1992-11-04 | 22 | Houston,Texas | AAA | 2012-2015 | - | 2014-16- 471-SEA | Stanford U. | Free Agent | (MLB) |
| Raymon Tenias | C | DSL Mariners 2 (Rk) | 5-8 | 185 | R-R | 1994-04-15 | 21 | Cumana,Venezuela | RK | 2015-2015 | - | (MLB) | |||
| Dylan Thompson | P | Azl Mariners (Rk) | 6-2 | 180 | R-L | 1996-09-16 | 18 | Myrtle Beach,South Carolina | A- | 2015-2017 | - | 2015- 4- 125-SEA | Minors | Tampa Bay Rays (Rk) | |
| Lance Thonvold | P | Everett (A-) | 6-4 | 225 | R-R | 1993-07-08 | 21 | Scottsdale,Arizona | A- | 2015-2018 | - | 2015-24- 725-SEA | Minnesota | Free Agent | - (MLB) |
| Andres Torres | P | Azl Mariners (Rk) | 6-3 | 185 | R-R | 1995-10-31 | 19 | Distrito Capital,Venezuela | A- | 2015-2017 | - | Minors | Seattle Mariners (A-) | ||
| Christopher Torres | SS | DSL Mariners 2 (Rk) | 5-11 | 170 | B-R | 1998-02-06 | 17 | Santiago,Dom Rep | A | 2015-2018 | - | 2014- UDFA-SEA | Minors | Miami Marlins (A) | |
| Daniel Torres | C | Clinton (A) Bakersfield (A+) | 6-0 | 175 | R-R | 1992-05-29 | 23 | Clearwater,Florida | AAA | 2011-2017 | - | 2013-20- 597-SEA | Saint Leo U. | Minors | Seattle Mariners (A+) |
| Mark Trumbo | 1B | Seattle (MLB) | 6-5 | 210 | R-R | 1986-01-16 | 29 | Orange,California | MLB | 2005-2018 | 2010-2018 | 2004-18- 533-ANA | Active | Baltimore Orioles (MLB) | |
| Ryan Uhl | 1B | Everett (A-) | 6-6 | 230 | R-R | 1993-05-26 | 22 | St. Marys,Pennsylvania | A- | 2012-2016 | - | 2015- 7- 215-SEA | Indiana Pennsylvania | Minors | Seattle Mariners (MLB) |
| Dylan Unsworth | P | Bakersfield (A+) Jackson (AA) | 6-1 | 170 | R-R | 1992-09-23 | 22 | Bothasig,South Africa | AAA | 2010-2018 | - | Free Agent | - (MLB) | ||
| Melchor Urquides | P | DSL Mariners 2 (Rk) | 6-0 | 180 | B-L | 1995-07-26 | 19 | Nogales,Mexico | RK | 2013-2015 | - | 2013- UDFA-SEA | Minors | Seattle Mariners (Rk) | |
| Nick Valenza | P | Clinton (A) Bakersfield (A+) | 5-10 | 180 | R-L | 1993-03-31 | 22 | Scottsdale,Arizona | A+ | 2011-2016 | - | 2011-18- 543-SEA | Free Agent | (MLB) | |
| Leurys Vargas | 1B | DSL Mariners (Rk) | 6-3 | 225 | L-R | 1996-08-30 | 18 | Bajos de Haina,Dom Rep | RK | 2013-2017 | - | 2012- UDFA-SEA | Free Agent | (MLB) | |
| Richard Vargas | P | Jackson (AA) | 6-3 | 170 | R-R | 1991-04-19 | 24 | Santo Domingo,Dom Rep | AA | 2010-2015 | - | Free Agent | (MLB) | ||
| Pedro Vasquez | P | DSL Mariners (Rk) | 6-4 | 190 | R-R | 1995-09-23 | 19 | Santo Domingo,Dom Rep | AA | 2015-2018 | - | Minors | Pittsburgh Pirates (A+) | ||
| Thyago Vieira | P | Clinton (A) | 6-2 | 210 | R-R | 1993-01-07 | 22 | Sao Paulo,Brazil | MLB | 2013-2018 | 2017-2018 | 2010- UDFA-SEA | Active | Chicago White Sox (MLB) | |
| Matt Walker | P | Azl Mariners (Rk) | 6-6 | 201 | R-R | 1994-09-28 | 20 | Fort Worth,Texas | AA | 2015-2018 | - | 2015-36-1085-SEA | Weatherford Col | Minors | Seattle Mariners (AA) |
| Taijuan Walker | P | Seattle (MLB) | 6-4 | 195 | R-R | 1992-08-13 | 22 | Yucaipa,California | MLB | 2010-2018 | 2013-2018 | 2010- 1- 43-SEA | Active | Arizona Diamondbacks (MLB) | |
| Chien-Ming Wang | P | Tacoma (AAA) | 6-3 | 230 | R-R | 1980-03-31 | 35 | Tainan,Taiwan | MLB | 2000-2016 | 2005-2016 | 2000- UDFA-NYA | Free Agent | (MLB) | |
| Nelson Ward | IF | Clinton (A) Bakersfield (A+) | 5-11 | 170 | L-R | 1992-08-06 | 22 | Marietta,Georgia | AA | 2012-2018 | - | 2014-12- 351-SEA | Georgia | Free Agent | (MLB) |
| Art Warren | P | Azl Mariners (Rk) | 6-3 | 210 | R-R | 1993-03-23 | 22 | Stryker,Ohio | AA | 2015-2018 | - | 2015-23- 695-SEA | Cincinnati, Ashland U. | Minors | Seattle Mariners (AA) |
| Gianfranco Wawoe | 2B | Clinton (A) Jackson (AA) | 5-11 | 170 | B-R | 1994-07-25 | 20 | Willemstad,Curacao | AAA | 2014-2017 | - | Free Agent | (MLB) | ||
| Rickie Weeks | 2B | Seattle (MLB) | 6-0 | 195 | R-R | 1982-09-13 | 32 | Daytona Beach,Florida | MLB | 2001-2017 | 2003-2017 | 2003- 1- 2-MIL | So.U. | Free Agent | (MLB) |
| NIck Wells | P | Everett (A-) | 6-5 | 180 | L-L | 1996-02-21 | 19 | Alexandria,Virginia | A+ | 2014-2018 | - | 2014- 3- 83-TOR | Minors | Seattle Mariners (A+) | |
| Jared West | P | Azl Mariners (Rk) | 6-6 | 200 | R-L | 1993-06-08 | 22 | The Woodlands,Texas | RK | 2015-2015 | - | 2015-29- 875-SEA | Houston, Louisiana St in Shreveport | (MLB) | |
| Jared West | P | Azl Mariners (Rk) | 6-6 | 220 | R-L | 1993-06-08 | 22 | - | Rk | 2015-2015 | - | 2015-29- 875-SEA | Louisiana St in Shreveport | Minors | Seattle Mariners (MLB) |
| Kyle Wilcox | P | Everett (A-) | 6-3 | 180 | R-R | 1994-06-14 | 21 | Sandy Hook,Connecticut | A+ | 2015-2018 | - | 2015- 6- 185-SEA | Bryant U. | Minors | Seattle Mariners (A+) |
| Tom Wilhelmsen | P | Tacoma (AAA) Seattle (MLB) | 6-6 | 190 | R-R | 1983-12-16 | 31 | Tucson,Arizona | MLB | 2003-2018 | 2011-2017 | 2002- 7- 199-MIL | Retired | (MLB) | |
| Austin Wilson | OF | Bakersfield (A+) | 6-4 | 210 | R-R | 1992-02-07 | 23 | Los Angeles,California | A+ | 2011-2017 | - | 2013- 2- 49-SEA | Stanford U. | Free Agent | (MLB) |
| Grady Wood | P | Bakersfield (A+) Jackson (AA) | 6-1 | 195 | R-R | 1990-05-18 | 25 | Junction City,Oregon | AA | 2012-2018 | - | 2012-10- 311-SEA | Western Oregon U., Chemeketa CC | Free Agent | (MLB) |
| Ryan Yarbrough | P | Azl Mariners (Rk) Clinton (A) Bakersfield (A+) | 6-6 | 205 | L-L | 1991-12-31 | 23 | Lakeland,Florida | MLB | 2014-2018 | 2018-2018 | 2014- 4- 111-SEA | Old Dominion U., Santa Fe CC | Active | Tampa Bay Rays (MLB) |
| Aneuris Zabala | P | Azl Mariners (Rk) | 6-2 | 175 | R-R | 1996-12-21 | 18 | Santo Domingo,Dom Rep | A | 2014-2018 | - | Minors | Cincinnati Reds (A) | ||
| Gianni Zayas | P | Azl Mariners (Rk) | 6-2 | 195 | R-R | 1994-04-18 | 21 | North Bergen,New Jersey | RK | 2015-2018 | - | 2015-35-1055-SEA | North Carolina St, Seminole St Florida, Florida International U. | Free Agent | (MLB) |
| Taylor Zeutenhorst | OF | Everett (A-) Clinton (A) Bakersfield (A+) | 6-4 | 205 | L-R | 1992-10-25 | 22 | Sheldon,Iowa | A+ | 2011-2018 | - | 2014-38-1131-SEA | Iowa | Free Agent | (MLB) |
| Jake Zokan | P | Bakersfield (A+) Jackson (AA) | 6-2 | 195 | L-L | 1991-04-27 | 24 | Columbia,South Carolina | AA | 2013-2018 | - | 2013- 9- 267-SEA | Col. Charleston | Free Agent | - (MLB) |
| Mike Zunino | C | Tacoma (AAA) Seattle (MLB) | 6-2 | 220 | R-R | 1991-03-25 | 24 | Cape Coral,Florida | MLB | 2010-2018 | 2013-2018 | 2012- 1- 3-SEA | Florida | Active | Tampa Bay Rays (MLB) |
