The 1983 Major League Baseball season was the seventh season in the history of the Seattle Mariners. They were seventh in the American League West at 60–102 (.370), 39 games behind, with the worst record in the major leagues. They became the first team to fail to sweep an opponent in any series.

In his third season as the Mariners' manager, Rene Lachemann was fired on June 25, succeeded by Del Crandall. At the time, the Mariners were 26–47 (.356), on an eight-game losing streak, and had the worst record in the majors. A former major league manager, Crandall was managing the Triple-A Albuquerque Dukes, the Pacific Coast League affiliate of the Los Angeles Dodgers.

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

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

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

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

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