A by-election for the seat of Subiaco in the Legislative Assembly of Western Australia was held on 10 November 1917. It was triggered by the death of the sitting member, Bartholomew Stubbs of the Labor Party, on 26 September 1917. The election was won by Samuel Brown, a member of the Subiaco Municipal Council who was standing for the Nationalist Party. Brown was one of six candidates endorsed by the Nationalists, and won the seat despite only polling 15.02 percent of the first-preference vote.