Seattle Mariners franchise seasons
49 available seasons. Historical team names follow each season's source article.
- 2025 Seattle Mariners — 54 roster players
- 2024 Seattle Mariners — 50 roster players
- 2023 Seattle Mariners — 56 roster players
- 2022 Seattle Mariners — 59 roster players
- 2021 Seattle Mariners — 63 roster players
- 2020 Seattle Mariners — 49 roster players
- 2019 Seattle Mariners — 67 roster players
- 2018 Seattle Mariners — 53 roster players
- 2017 Seattle Mariners — 61 roster players
- 2016 Seattle Mariners — 54 roster players
- 2015 Seattle Mariners — 51 roster players
- 2014 Seattle Mariners — 44 roster players
- 2013 Seattle Mariners — 47 roster players
- 2012 Seattle Mariners — 38 roster players
- 2011 Seattle Mariners — 47 roster players
- 2010 Seattle Mariners — 47 roster players
- 2009 Seattle Mariners — 46 roster players
- 2008 Seattle Mariners — 44 roster players
- 2007 Seattle Mariners — 43 roster players
- 2006 Seattle Mariners — 49 roster players
- 2005 Seattle Mariners — 47 roster players
- 2004 Seattle Mariners — 48 roster players
- 2003 Seattle Mariners — 37 roster players
- 2002 Seattle Mariners — 40 roster players
- 2001 Seattle Mariners — 35 roster players
- 2000 Seattle Mariners — 37 roster players
- 1999 Seattle Mariners — 51 roster players
- 1998 Seattle Mariners — 47 roster players
- 1997 Seattle Mariners — 47 roster players
- 1996 Seattle Mariners — 49 roster players
- 1995 Seattle Mariners — 46 roster players
- 1994 Seattle Mariners — 43 roster players
- 1993 Seattle Mariners — 48 roster players
- 1992 Seattle Mariners — 48 roster players
- 1991 Seattle Mariners — 38 roster players
- 1990 Seattle Mariners — 43 roster players
- 1989 Seattle Mariners — 40 roster players
- 1988 Seattle Mariners — 40 roster players
- 1987 Seattle Mariners — 41 roster players
- 1986 Seattle Mariners — 40 roster players
- 1985 Seattle Mariners — 42 roster players
- 1984 Seattle Mariners — 40 roster players
- 1983 Seattle Mariners — 41 roster players
- 1982 Seattle Mariners — 40 roster players
- 1981 Seattle Mariners — 37 roster players
- 1980 Seattle Mariners — 34 roster players
- 1979 Seattle Mariners — 35 roster players
- 1978 Seattle Mariners — 34 roster players
- 1977 Seattle Mariners — 43 roster players