James Leslie "Les" McMahon (26 February 1930 – 23 January 2015) was an Australian politician. Born in Sydney, he was a plumber, gasfitter and drainer and then an organiser for the Plumbers and Gasfitters Employees Union of Australia (NSW branch). He was elected to Sydney City Council in 1967, Leichhardt City Council in 1968, and Sydney City Council again in 1971.