Douglas William Piatt (born September 26, 1965) is an American former Major League Baseball pitcher. He appeared in 21 games for the Montreal Expos in , all in relief. After posting a 2.60 earned run average and striking out 29 batters in 34 innings, Piatt never received another chance in the major leagues. He continued to pitch in the minor leagues until , finishing his career with the independent Waterbury Spirit.