The 2021 Seattle Mariners season was the 45th season in franchise history. The Mariners played their 22nd full season (23rd overall) at T-Mobile Park, their home ballpark in Seattle, Washington. The M's entered this season with the longest active playoff drought in the four major North American professional sports leagues, attempting to make their first postseason in twenty years. Seattle is the only current Major League Baseball (MLB) franchise without a World Series appearance. Despite posting a 90–72 record, their best since the 2003 season, the Mariners were eliminated from postseason contention for the 20th consecutive season after a loss to the Angels, and both the Yankees and Red Sox clinched the two wild card spots on the last day of the season. This season was the second time duri