The 2025 Seattle Mariners season was the 49th season in franchise history and their 26th full season (27th overall) at T-Mobile Park, their home ballpark in Seattle, Washington. The Mariners won their first American League (AL) West divisional title and Division Series since 2001.
Catcher Cal Raleigh had an unprecedented home run hitting season, finishing the regular season with 60 home runs. He broke the franchise record for home runs (set by Ken Griffey Jr.) and major league records for home runs by a catcher and switch hitter in a season. He also won the Home Run Derby, which Griffey won three times.
Raleigh, Randy Arozarena, Julio Rodríguez, Bryan Woo, and Andrés Muñoz were selected to play in the All-Star Game. Raleigh was named the AL Player of the Month for June, and Muñoz was named the AL Reliever of the Month for March/April. Raleigh won the Silver Slugger Award, and he and Rodríguez were named to the All-MLB Team. Woo and Muñoz were named to the All-MLB second team.
On August 9, the Mariners retired the number 51 worn by Ichiro Suzuki, following his induction into the National Baseball Hall of Fame in July. This was the fourth number retired by the team. The Mariners played in the MLB Little League Classic on August 17, losing to the New York Mets.
The Mariners clinched a postseason berth for the first time since 2022 on September 23, with a victory over the Colorado Rockies. The next night, the team won the AL West division for the fourth time in franchise history.
The Mariners defeated the sixth seed Detroit Tigers in the AL Division Series (ALDS). With their win in Game 2, the Mariners won their first home postseason game since Game 5 in the 2001 ALDS. The Mariners won the series in 5 games, reaching the AL Championship Series for the first time since 2001, where they faced the Toronto Blue Jays. Despite winning three of the first five games, the Mariners squandered 2–0 and 3–2 series leads, losing in Game 7 after allowing a go-ahead home run to George Springer. The loss extended the Mariners' drought of never winning the AL pennant.
The Mariners drew an average home attendance of 31,333, declining for the second consecutive year.
Offseason
Transactions
November 1: The Mariners declined Jorge Polanco's $12 million option for the 2025 season. November 15: The Mariners re-signed Casey Lawrence to a minor league contract. November 19: The Tampa Bay Rays traded infielder Austin Shenton to the Mariners for cash. Shenton took the roster spot formerly held by reliever J.T. Chargois, who was traded with Shenton to the Rays in 2021. November 22: The Mariners did not tender contracts to Chargois, Josh Rojas, Austin Voth, and Sam Haggerty, making them free agents. All four players signed with different teams. November 26: The Mariners announced their coaching staff for 2025. Changes from the end of 2024 included Kevin Seitzer replacing Edgar Martínez as hitting coach, Manny Acta moving from third base coach to bench coach, and Eric Young Jr. becoming first base coach. (The team's previous bench coach, Brant Brown, was fired at the end of May 2024.) December 14: The Mariners signed Sauryn Lao to a minor league contract. December 19: The Mariners claimed catcher Nick Raposo off waivers. January 8, 2025: Reliever Hagen Danner was claimed off waivers. January 13: Donovan Solano signed a one-year, $3.5 million contract. Austin Kitchen was designated for assignment and later outrighted to the Triple-A Tacoma Rainiers. January 14: The Chicago Cubs traded infielder Miles Mastrobuoni to the Mariners for cash. Raposo was designated for assignment. He cleared waivers and was sent outright to Tacoma on January 17. January 15: The Baltimore Orioles traded catcher Blake Hunt to the Mariners for cash. Samad Taylor was designated for assignment and subsequently sent outright to Tacoma on January 21. January 21: The Kansas City Royals traded reliever Will Klein to the Mariners for international bonus pool space. The Mariners designated pitcher Tyler Jay, who had been a waiver claim earlier in January. Jay was outrighted to Tacoma. January 28: The Mariners signed pitcher Luis F. Castillo to a minor league contract. February 3: The Mariners re-signed Polanco to a one-year, $7.75 million contract with up to $3.5 million in incentives. On that day, the Cincinnati Reds also traded reliever Casey Legumina to the Mariners for cash. Cade Marlowe and Jhonathan Díaz were both designated for assignment, though both remained with the organization on minor league deals. February 20: The Mariners signed first baseman Rowdy Tellez to a minor league contract. March 2: Pitcher Jackson Kowar was placed on the 60-day injured list. Reliever Seth Martinez was claimed off waivers from the Miami Marlins. Martinez returned to Miami on March 15. March 23: The Mariners released outfielder Mitch Haniger. March 25: Catcher Cal Raleigh signed a six-year, $105 million contract extension.
Spring training Spring Training non-roster inviteesPlayer Position2024 team(s)Peyton AlfordPitcherArkansas Travelers Luis F. CastilloPitcherOrix BuffaloesTyler ClevelandPitcherEverett AquaSoxHunter CrantonPitcherModesto NutsLogan EvansPitcherArkansas TravelersNeftali FelizPitcherCaliente de Durango/Leones de YucatanJosh FlemingPitcherPittsburgh PiratesShintaro FujinamiPitcherSyracuse MetsBrandyn GarciaPitcherArkansas TravelersJesse HahnPitcherOklahoma City Baseball Club/Tacoma RainiersAustin KitchenPitcherMiami MarlinsSauryn LaoPitcherOklahoma City Baseball ClubCasey LawrencePitcherTacoma RainiersAdonis MedinaPitcherRochester Red WingsDrew PomeranzPitcherOklahoma City Baseball ClubDauris ValdezPitchernoneJosh CaronCatcherModesto NutsConnor CharpingCatcherEverett AquaSoxHarry FordCatcherArkansas TravelersJacob NottinghamCatcherOlmecas de Tabasco/Charros de JaliscoNick RaposoCatcherMemphis Redbirds/Buffalo BisonsMichael ArroyoInfielderEverett AquaSoxNick DunnSecond basemanMemphis RedbirdsColt EmersonShortstopEverett AquaSoxBrock RoddenInfielderArkansas TravelersRowdy TellezFirst basemanPittsburgh PiratesBen WilliamsonThird basemanArkansas TravelersCole YoungSecond basemanArkansas TravelersLazaro MontesOutfielderEverett AquaSoxSpencer PackardOutfielderTacoma RainiersRhylan ThomasOutfielderSyracuse Mets/Tacoma RainiersSamad TaylorUtility playerSeattle Mariners Regular season Season standings American League West
American League Wild Card
Record vs. opponents Record vs. American League
Record vs. National League
Season summary March/April The Mariners started poorly, going 4–8 to begin the season, including being swept by the San Francisco Giants. Starting with an 8th inning grand slam by Randy Arozarena on April 9, the team's performance improved enough to lead the AL West at the end of the month. The team won their last seven series of the month. Rowdy Tellez hit home runs in three consecutive games at Rogers Centre, his former home ballpark, to help win a series against the Toronto Blue Jays. The Mariners then defeated Boston Red Sox ace Garrett Crochet in another series win. Several players had career-best performances, with Dylan Moore and Jorge Polanco winning back-to-back AL Player of the Week awards. Their offense, along with Cal Raleigh's 10 home runs, carried the Mariners. Closer Andrés Muñoz tied for the MLB lead with 11 saves and did not allow a run, winning the AL Reliever of the Month Award.
The team was beset by injuries: starting pitcher George Kirby and relievers Matt Brash and Troy Taylor started the season on the injured list, and regulars Víctor Robles, Logan Gilbert, Ryan Bliss, Moore, Luke Raley, and Gregory Santos ended April injured. Polanco also dealt with a knee injury that prevented him from switch hitting or playing defense. As part of the team's reinforcements, Ben Williamson, Logan Evans, and Sauryn Lao all made their major league debuts.
May The Mariners won their ninth consecutive series with a five-run deficit to defeat the Athletics 6–5 on May 8. However, the team then lost five of six games at home, including being swept by the Toronto Blue Jays. In the final game of the homestand, Aaron Judge of the New York Yankees hit his league-leading 15th home run. Reversing that streak, the Mariners then won five of six on the road, including sweeping the San Diego Padres to open the Vedder Cup and winning two against the Chicago White Sox. Julio Rodríguez hit a decisive grand slam on May 19.
However, the team ended the month in a slump, losing three out of four games in Houston to the Astros and three out of five games at home. On May 30, Andrés Muñoz blew his third save of the month as the team fell behind Houston in the AL West. On May 31, Cole Young had a walk-off in his MLB debut, a fielder's choice in a 5–4, 11-inning win over the Minnesota Twins. Earlier in that game, Cal Raleigh hit his 22nd home run, tied for the MLB lead with Shohei Ohtani.
Raleigh led the team, batting .304 with 12 home runs and 26 RBI in May. J. P. Crawford moved up to the leadoff role, hitting a first-pitch home run on May 4. The team continued to look for an everyday right fielder, promoting Rhylan Thomas for his MLB debut on May 2, then claiming Leody Taveras off waivers from the Texas Rangers. The team's first base platoon of Rowdy Tellez and Donovan Solano also struggled.
On the mound, George Kirby made his first start of the season on May 22, but Bryce Miller briefly went on the injured list, returning on May 31. Brash returned from injury, pitching on May 3 for the first time since the 2023 season. Other bullpen reinforcements included Jackson Kowar, who made his Mariners debut on May 28, Casey Lawrence, who returned to the team after being claimed by Toronto, and Jesse Hahn, who was called up on May 21 when Lawrence was designated for assignment for the fifth time that season. Blas Castaño made his MLB debut, pitching the final three innings of a 9–0 loss to the Washington Nationals on May 28. Despite the blown saves, Muñoz allowed his first earned run on May 30 and led the majors with 17 saves.
June A Randy Arozarena walk-off single, following another Andrés Muñoz blown save against the Twins on June 1 put the Mariners back in first in the AL West. However, a 1–8 stretch put the Mariners behind Houston. The Mariners were swept on the road in Baltimore, won one game out of three against the Los Angeles Angels in Anaheim, then were swept by the Arizona Diamondbacks, with Josh Naylor hitting a walk-off grand slam off Carlos Vargas on June 9 and Eugenio Suárez hitting a grand slam on June 11. The Mariners then swept the Cleveland Guardians at home, with Jorge Polanco hitting a walk-off single off closer Emmanuel Clase on June 14. The next day, Crawford hit a home run on Father's Day. The Boston Red Sox then won two of three in Seattle, with the lone win coming as Cal Raleigh hit a grand slam and Bryan Woo threw 7 shutout innings on June 17.
The Mariners started their road trip strong, winning two games against the Chicago Cubs. In the rubber match on June 22, Donovan Solano and Dominic Canzone both hit two home runs. Seattle won its first two games in Minnesota, clubbing four home runs on June 23, before losing the final two games of the series to the Twins. Returning home, the Mariners won two 12-inning games against the Texas Rangers and beat the Kansas City Royals on June 30. In that game, Raleigh hit his 33rd home run, tied for third most by any player at the end of June. Arozarena also hit his 100th major league home run.
Raleigh was named the AL Player of the Month for June. He hit .300 and led the AL with 11 home runs and had a .690 slugging percentage and 3 stolen bases. He also committed to participate in the Home Run Derby in July. He was also named the AL Player of the Week on June 1 and June 22.