William John Finley Warren (December 14, 1873[1] – 1963[2]) was a farmer, rancher and political figure in Saskatchewan. He represented Thunder Creek in the Legislative Assembly of Saskatchewan from 1921 to 1925 as a Progressive Party member.
He was born in Balderson[2] near Perth, Ontario, the son of Richard Warren and Margaret James, and was educated at the Saskatchewan Agricultural College.[1] He settled in Balbeck, Saskatchewan in 1906.[3] In 1911, Warren married Annie M. James. He was president of the Moose Jaw Agricultural Society,[1] of the Saskatchewan Registered Seed Grower's Association and of the Saskatchewan Agricultural Societies' Association.[3] Warren was defeated by Robert Scott Donaldson when he ran for reelection to the provincial assembly in 1925.[4]