Cyril McMahon nicknamed "Kelly" was an Australian professional rugby league footballer who played in the 1940s and 1950s.
He played in the NSWRFL premiership for North Sydney and Manly-Warringah as a five-eighth.
That same year McMahon played at five-eighth in North's 1943 grand final defeat against Newtown which would prove to be the club's last grand final appearance before exiting the competition in 1999.
In 1947, McMahon joined Manly and played in their inaugural game against Western Suburbs which Wests won 15–13.
This rugby league football biography relating to an Australian born in the 1920s is a stub.