Assistant coach Dean Evason was named interim head coach.
At 27-23-7, the Wild are three points out of a playoff spot in the Western Conference. They've gone 7-3-1 over their last 11 games.
Boudreau's dismissal represents the eighth coaching change in the NHL this season. Since the end of the 2018-19 campaign, 15 of the league's 31 teams have changed bench bosses.
The 65-year-old Boudreau, who was in his fourth season with the Wild, led the club to playoff appearances in 2017 and 2018 but failed to advance past the first round each time.
Among coaches who've overseen at least 500 games, Boudreau owns the third-best points percentage in NHL history behind Scott Bowman and Jon Cooper. He coached the Washington Capitals and Anaheim Ducks before landing with Minnesota in 2016.