Incumbents
- Monarch – Elizabeth II
- Governor General – Vincent Massey
- Prime Minister – Louis Saint Laurent then John Diefenbaker
- Premier of Alberta – Ernest Manning
- Premier of British Columbia – W.A.C. Bennett
- Premier of Manitoba – Douglas Campbell
- Premier of New Brunswick – Hugh John Flemming
- Premier of Newfoundland – Joey Smallwood
- Premier of Nova Scotia – Robert Stanfield
- Premier of Ontario – Leslie Frost
- Premier of Prince Edward Island – Alex Matheson
- Premier of Quebec – Maurice Duplessis
- Premier of Saskatchewan – Tommy Douglas
Read more about this topic: 1957 In Canada