2023 Seattle Mariners season

The 2023 Seattle Mariners season was the 47th season in franchise history. The Mariners played their 24th full season (25th overall) at T-Mobile Park, their home ballpark in Seattle, Washington. Despite Seattle having shown signs of competitiveness, and having a 90.2% chance to make the playoffs on September 2 while having 1st place in the AL West, the Mariners missed the playoffs for the 22nd time in 23 seasons.

Rule changes
Pursuant to the CBA, rule changes for the season:


 * institution of a pitch clock between pitches
 * limits on pickoff attempts per plate appearance
 * limits on defensive shifts requiring two infielders to be on either side of second and be within the boundary of the infield
 * larger bases (18 in squares; previously 15 in)

Batting
Note: G = Games played; AB = At bats; R = Runs; H = Hits; 2B = Doubles; 3B = Triples; HR = Home runs; RBI = Runs batted in; SB = Stolen bases; BB = Walks; AVG = Batting average; SLG = Slugging average Source:

Pitching
Note: W = Wins; L = Losses; ERA = Earned run average; G = Games pitched; GS = Games started; SV = Saves; IP = Innings pitched; H = Hits allowed; R = Runs allowed; ER = Earned runs allowed; BB = Walks allowed; SO = Strikeouts Source: