Warren Ryan played one game for St George as a lock forward in 1965.
A Commonwealth Games Shot Put representative in 1962, Warren joined Cronulla in 1967 to play 22 games from 1967 to 1968.
In 1969, Warren joined Western Suburbs in Wollongong and played until 1973. Warren was captain-coach in 1972 and 1973.
He captained Country in 1972. In 1974, Warren coached Collegians.
Warren joined Western Suburbs in 1977 as the Under 23s coach and in 1979 became first grade coach of Newtown. He coached Newtown to the Grand Final in 1981.
After one season break, Warren was appointed coach of Canterbury in 1984 and coached the team to Premierships in 1984 and 1985. In 1986, Warren coached the team to the Grand Final.
After an unsuccessful 1987, Warren joined Balmain to coach them to the Grand Finals in 1988 and 1989.
In 1991, Warren joined Western Suburbs for four seasons. After a break of five seasons, Warren joined Newcastle to coach the 1999 and 2000 seasons.