William Frederick Farrar Crabtree (31 May 1915 – 12 July 2001) was an Australian politician. He was a member of the New South Wales Legislative Assembly from 1953 until 1983 and represented the Labor Party. Crabtree defeated Douglas Cross the incumbent member for the seat of Kogarah, at the 1953 election. He retained the seat for the Labor Party at the next 10 elections. In the government of Neville Wran he was Minister for Lands and Minister for Environment between 1976 and 1980 and Minister for Police and Minister for Services from 1980 to 1981.