Anthony Markham Trethowan (19 December 1945 – 6 May 2015) was an Australian politician and Anglican minister who was a Liberal Party member of the Legislative Assembly of Western Australia from 1980 to 1986, representing the seat of East Melville.
His maternal grandfather was Claude de Bernales, a mining entrepreneur of Basque descent.
Prior to entering politics, he was an executive director of the Austmac group of companies, and also a pilot officer in the Air Force Reserve.
[2] Trethowan entered parliament at the 1980 state election, replacing Sir Des O'Neil (a former deputy premier).
At the 1983 state election, Trethowan won his seat with 53.6 percent of the first-preference vote, defeating candidates from the Labor Party (Carmen Lawrence, a future premier) and the Australian Democrats (Shirley de la Hunty, a former Olympic athlete).