Donald Mark Prince (born April 5, 1938) is an American former professional baseball player. He had a seven-year (1958–1964) active career, but appeared in only one inning of one Major League Baseball game for the 1962 Chicago Cubs. He stood 6 feet 4 inches (1.93 m) tall and weighed 200 pounds (91 kg) and attended Campbell University, Buies Creek, North Carolina.
Prince's Major League audition came after a mediocre 1962 season with the Cubs' Triple-A Salt Lake City Bees affiliate, where he won 10 of 24 decisions and had a high earned run average of 5.31, largely as a starting pitcher. In his one MLB game, he pitched in relief in the ninth inning of a 4–1 loss to the New York Mets at the Polo Grounds. He issued a base on balls to the first man he faced, Joe Christopher, then hit the next batter, Frank Thomas. But Jim Hickman got Prince off the hook by grounding into a 1-6-3 double play and Sammy Drake bounced out to second.
Prince then returned to the minor leagues for the 1963–1964 seasons before retiring from baseball.
In 1996, Prince was convicted in a murder for hire plot in the Federal District Court in South Carolina. Prince received a 17 and a half year sentence for attempting to have two people murdered by an undercover police officer he believed to be a hit man.