Quincy David "Quin" Epperly (March 3, 1913 – January 7, 2001) was an American racing car constructor. In the late 1940s, he went to work for Frank Kurtis building racing car bodies; this led to a lifelong career in the racing business. During the mid-1950s Epperly opened his own shop, where he came up with a radical approach in racing car design, by placing the four-cylinder Offenhauser engine on its side, rather than in the upright position. Epperly cars competed in five FIA World Championship races: the 1955, 1957, 1958, 1959 and 1960 Indianapolis 500, winning the race in 1957 and 1958.