Archie Richard "Happy" or "Hap" McKain (May 12, 1911 – May 21, 1985) was a left-handed Major League Baseball pitcher with the Boston Red Sox, Detroit Tigers and the St. Louis Browns between 1937 and 1943. McKain was born in Delphos, Kansas, in 1911. McKain made his major league debut with the Red Sox in 1937. In two seasons with Boston, he compiled a 13-12 record and a 4.60 ERA. In August, 1941, the Tigers sold McKain to the St. Louis Browns. He appeared in 18 games for the Browns in 1941 and 1943. When the Browns traded him to Brooklyn in July 1943, he retired from baseball.