The 1990 Seattle Mariners season was the 14th for the Seattle Mariners in Major League Baseball. Under second-year manager Jim Lefebvre, they finished fifth in the American League West at .470. It was the second-best record in the M's history up to that point in time; the win total was one behind the club record set in 1987. The Mariners hit six grand slams, the most in MLB in.

Offseason

Regular season

Opening Day starters

Season standings

Record vs. opponents

Notable transactions

Roster

The Griffeys

Line Score

August 31, Kingdome, Seattle, Washington

Batting

Pitching

Player stats

Batting

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''

Pitching

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

Farm system