He served in the Legislative Assembly of Manitoba as a Liberal from 1909 to 1922, and was a cabinet minister in the government of Tobias Norris.
He was educated at King Edward VI school in Sherbourne, England, and moved to Canada in 1882.
Malcolm was elected to replace former Liberal house leader Charles Mickle in the constituency of Birtle.
[3] The Conservative Party, which had governed Manitoba since 1900, was forced to resign from office in 1915 amid a serious corruption scandal.
The Liberals won a landslide majority government in the 1915 provincial election, with Malcolm receiving more than twice as many votes as his Conservative opponent.