Peter McMahon AM (born 16 July 1931) is a former Australian politician. He was a Labor member of the New South Wales Legislative Council from 1973 to 1981. McMahon was born in Wagga Wagga to Otho Thomas McMahon and Ida Braunsdorf. He was educated at Ladysmith Public School (1936–1939), Mosman Public School (1940–1942) and North Sydney Technical High School (1943–1947), leaving at the age of sixteen. He joined the Citizen Military Forces in 1949 and became a sergeant in the 7th Field Regiment. In 1954, he joined the Labor Party, and visited Britain and Europe in 1961 under a scholarship from the Imperial Relations Trust. He became active in the union movement and internal Labor politics.