Robert William Humphreys (born August 18, 1935) is a former professional baseball player. Humphreys was a pitcher over parts of nine seasons (1962–1970) with the Detroit Tigers, St. Louis Cardinals, Chicago Cubs, Washington Senators and Milwaukee Brewers. Humphreys was a member of the 1964 World Series champion Cardinals. An alumnus of Hampden-Sydney College, for his career he compiled an 27–21 record with a 3.36 earned run average and 364 strikeouts in 319 appearances, all but four of which came as a relief pitcher.
After his playing career ended, Humphreys remained in baseball as a player development director and minor league field coordinator for the Brewers and Cardinals.