1985 Seattle Mariners season

The Seattle Mariners season was their ninth since the franchise creation. They finished sixth in the American League West with a record of .450.

Regular season

 * July 9: Against the Toronto Blue Jays at the Kingdome in Seattle, Jays catcher Buck Martinez executed a double play by tagging out two runners at home plate. In the third inning, Phil Bradley was on second when Gorman Thomas singled. Bradley was tagged out at home, on a throw from Jesse Barfield to Martinez with a collision in which Martinez broke his ankle; he was sitting on the ground in agony and threw the ball to third base in an attempt to tag out Thomas. The throw went into left field and Thomas continued running; left fielder George Bell threw the ball back to Martinez, still seated on the ground in pain, who tagged Thomas out.

Notable transactions

 * June 3, 1985: Mike Schooler was drafted by the Mariners in the 2nd round of the 1985 Major League Baseball Draft.
 * June 20, 1985: Mike Stanton was released by the Mariners.

Starters by position
''Note: Pos = Position; G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in''

Other batters
''Note: G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in''

Starting pitchers
Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Other pitchers
Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Relief pitchers
Note: G = Games pitched; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts