Watson Montgomery Crosby (June 10, 1857 – March 19, 1897) served as the reeve of the Rural Municipality of Wallace and as a member of the Legislative Assembly of Manitoba for the constituency of Dennis.
His grandfather, Donald Montgomery, served as member of the Legislative Assembly of Prince Edward Island and represented Prince Edward Island as a member of the Senate of Canada.
Crosby moved to Manitoba in 1879 and settled on a farm near Virden.
He was elected as a Councillor for the Rural Municipality of Wallace and served as Reeve from 1893 to 1896.
[3] Crosby held his seat in the Legislative Assembly of Manitoba until his death.