Donald Glenn Horn (born March 9, 1945) is a former National Football League quarterback. He was a first round pick All American out of San Diego State University by the Green Bay Packers, but his NFL career was less impressive because he only threw for 3,369 yards and 20 touchdowns in 8 seasons. He finished his pro career in 1975 with the Portland Thunder of the up-start WFL, where he completed 158 of 272 passes for 1742 yards and 11 TDs (and 12 picks.)