Dontrelle Wayne Willis (born January 12, 1982, in Oakland, California), nicknamed "D-Train" and "D-Money," is a starting pitcher for the Detroit Tigers organization.

Willis attended Encinal High School in Alameda, California, where he played baseball for four years. He is the son of Clinton Ostah, a former minor league player in the 1970s. He was drafted by the Chicago Cubs in the 8th round of the 2000 Major League Baseball Draft.

On March 27, 2002, the Cubs traded Willis (then a minor leaguer), fellow pitchers Julián Tavárez and José Cueto, and catcher Ryan Jorgensen to the Florida Marlins, in exchange for pitchers Matt Clement and Antonio Alfonseca.