Greg Leffler (born December 27, 1951 in Winchester, Indiana), is a former driver in the CART Championship Car series. He raced in the 1980-1983 seasons, with 13 career starts, including the 1980 Indianapolis 500. He finished in the top ten twice, with his best finish in 6th position in 1982 at Riverside. In 1979, Leffler was the USAC Sprint Car Series Champion.