The Seattle Mariners have completed 45 seasons of professional baseball in the West division of Major League Baseball (MLB)'s American League (AL) since they began play in 1977. From April 6, 1977, until June 27, 1999, the Mariners played in Seattle's Kingdome. Since July 15, 1999, the Mariners have played at T-Mobile Park (formerly Safeco Field). Their name reflects their home city's coastal and marine culture.
An expansion team created as a result of a breach of contract lawsuit involving the Seattle Pilots' 1969 departure after just one year in Seattle, the Mariners finished each of their first fourteen seasons with a losing record. However, after Seattle won its division and a playoff berth for the first time in , they have enjoyed sporadic success, making the playoffs four more times but never advancing beyond the American League Championship Series (ALCS); the team tied an MLB record winning 116 games in 2001 but then missed the playoffs for the next 21 years. When the drought ended in 2022, it was longest active drought in MLB and in all of the major league North American sports. They again missed the playoffs the next year however in 2023. As of the end of 2023, the Seattle Mariners are now the only team in Major League Baseball to have never make it the World Series.
Table Key
Regular season results
Record by decade
The following table describes the Mariners' MLB win–loss record by decade.
Source: Baseball-Reference.com's Seattle Mariners History & Encyclopedia
Postseason record by year
The Mariners have made the postseason five times in their history, with their first being in 1995 and the most recent being in 2022.