Ronald Earl Willis (July 12, 1943 – November 21, 1977) is a former professional baseball player. He was a pitcher over parts of 5 seasons (1966–1970) with the St. Louis Cardinals, Houston Astros and San Diego Padres. Willis was a member of the 1967 World Series champion Cardinals. For his career he compiled an 11–12 record with a 3.32 earned run average and 128 strikeouts in 188 appearances, all as a relief pitcher.
Willis was born in Willisville, Tennessee and later died in Memphis, Tennessee at the age of 34 from a brain tumor.