Dontrelle Wayne Willis (born January 12, 1982), nicknamed "The D-Train", is an American professional baseball pitcher for the Baltimore Orioles organization. Willis is notable for his success during his first few years in the league and for his unconventional pitching style, which includes a high leg kick and exaggerated twisting away from the batter. Willis was named the 2003 National League Rookie of the Year.

Growing up in Alameda near Oakland, Willis rooted for the Oakland A's as a kid. His mother Joyce was a soft ball catcher for her high school team. Willis' favorite player was former Oakland A's pitcher, Dave Stewart. 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. In Willis' senior year, he went 12–1 with a 0.83 earned run average in 70 innings. Scouts never doubted his talents, but rather his unusual pitching mechanics. One scout even called him a "Poor man's CC Sabathia." He was drafted by the Chicago Cubs in the 8th round of the 2000 Major League Baseball Draft. In 2001, Willis was bumped up to the Boise Hawks of the Northwest League. He finished with 8 wins and a 2.98 ERA. Opposing hitters only batted .217 against Willis. In a Baseball America poll, several NWL managers called Willis Boise's best player.^{[citation needed]}