Thomas James O'Neill (2 June 1882 – 16 October 1965) was a Liberal party member of the House of Commons of Canada.
He was born in Winnipeg, Manitoba and became a locomotive engineer by career.
He also served on the General Committee of Adjustment for Canadian Pacific Railway.
He was an active supporter of labour unions, particularly the Brotherhood of Locomotive Engineers.
He was defeated by Davie Fulton of the Progressive Conservative party in the 1945 election.