Michael Dwain DeJean (/ˈdeɪʒɒn/; born September 28, 1970) is a former right-handed relief pitcher in Major League Baseball.

In 1992, while playing for Livingston in the Division II College World Series, DeJean pitched to two batters, retiring both.

He was selected in the 24th round of the 1992 amateur draft by the New York Yankees and signed to a professional contract as a pitcher.

DeJean achieved modest success as a closer for the Milwaukee Brewers in 2001 and 2002, but struggled mightily during brief tenures with the St. Louis Cardinals and Baltimore Orioles.

After signing a minor league contract with the Houston Astros during the 2007-2008 off-season, Dejean was released before appearing in a game.