The 1977 Seattle Mariners season was the first season in franchise history, which was established via the 1977 Major League Baseball expansion. The creation of the Mariners brought baseball back to Seattle, which had been without a major league team since the Seattle Pilots left for Milwaukee to become the Brewers in April 1970.

The Mariners ended the 1977 season by narrowly avoiding last place (held by the Oakland Athletics), finishing sixth in the American League West with a record of 64–98 (.395), 38 games behind the AL West champion Kansas City Royals.

April 6, Kingdome, Seattle, Washington

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