The 2019 Seattle Mariners season was the 43rd season in franchise history. The Mariners played their twentieth full season and twenty-first overall at T-Mobile Park, their home ballpark. The Mariners entered the season with the longest active playoff drought in the four major North American professional sports and again failed to make their first postseason appearance since 2001. The Mariners started the season with a 13–2 record, their best start in franchise history. However, they went 55–92 after their great start, finishing last in the AL West for the first time since 2012 and falling out of the playoffs once again.