Forrest was an electoral district of the Legislative Assembly in the Australian state of Western Australia from 1904 to 1950.
It was based in the South West region of the state, in the timber milling areas near the town of Dwellingup.
From the first time it was contested at the 1904 state election, the district was always a reliable Labor Party seat.
The by-election to replace him was won by Labor candidate Thomas Moore, who stood unopposed.
May Holman—the first female representative of an Australian parliament to belong to the Labor Party—held the seat until her death in a car accident on the day of the 1939 state election.