Seattle Mariners Logo
The Seattle Mariners are an American professional baseball team based in Seattle, Washington. They compete in Major League Baseball (MLB) as a member club of the American League (AL) West division. The team joined MLB as an expansion team in 1977, and played their home games in the Kingdome until 1999. Since 2000, they have played at T-Mobile Park. The Mariners have never won a World Series championship, but they have made two playoff appearances, in 1995 and 2001.