2005 Big Sky Conference men's basketball tournament

The 2005 Big Sky men's basketball tournament was played from March 5 to March 9. The First Round of the tournament was held at the higher seed's home arena, and the semi-finals and championship were held at the Memorial Coliseum in Portland, Oregon, which is the home of regular season champion Portland State. The top 6 teams from regular season play qualified and the top 2 teams received a bye to the semi-finals. The tournament was won by Montana and they received an automatic bid to the 2005 NCAA Men's Division I Basketball Tournament.