Joseph Edward Luther (born January 2, 1957 in Gardena, California) is a former American football quarterback in the National Football League. He was drafted by the San Diego Chargers in the fourth round of the 1980 NFL Draft. He played college football at San Jose State. Luther was a backup quarterback behind Dan Fouts with the Chargers. He also played for the Indianapolis Colts and the Jacksonville Bulls in 1985 of the USFL.