James O'Brien (August 3, 1836 – May 28, 1903) was a Canadian merchant, wholesaler, and politician.
Born in Aughnagar, County Tyrone, Ireland, O'Brien was educated there and moved to Canada in 1850.
In 1858, he started business in the wholesale clothing and dry goods trade in Montreal.
He retired from that business in 1893.
He was a director of the Montreal City and District Savings Bank, the Royal Victoria Life Insurance Company, and also a member of the Board of Trade.
He was a Life Governor of the Montreal General Hospital, of the Western and Notre Dame Hospitals, and a trustee of St.