1978 Seattle Mariners season

1978 Seattle Mariners
LeagueAmerican League
DivisionWest
BallparkKingdome
CitySeattle, Washington
Record56–104 (.350)
Divisional place7th
OwnersDanny Kaye
General managersLou Gorman
ManagersDarrell Johnson
TelevisionKING-TV 5
RadioKVI 570 AM
(Dave Niehaus, Ken Wilson)

The 1978 Seattle Mariners season was the second in franchise history. The Mariners ended the season by finishing seventh in the American League West with a record of 56–104 (.350).