William "Bill" Mackrides (born July 8, 1925) is a former American football quarterback for the Philadelphia Eagles of the National Football League. He helped the Eagles win the 1948 and 1949 NFL Championships. Mackrides played college football for the University of Nevada, Reno and led the nation in passing in 1947. In his last season in 1953, Mackrides played for the Pittsburgh Steelers and was the last Steeler to wear uniform number 13 in a regular season game until punter Jeremy Kapinos wore that number in 2010.