This is an article about the Canadian Premier. See John Buchanan (American_politician) for an article about the 2004 American presidential candidate.

John Maclellan Buchanan (born April 22, 1931) was a lawyer and politician.

Buchanan graduated from Mount Allison University in 1954 with a Bachelor of Science Degree and an Engineering Certificate. He then went on to study at Dalhousie Law School and after graduating in 1958 entered the practise of law where he was appointed Queen's Counsel in 1972.

He was first elected to the Nova Scotia legislature in 1967. He became leader of the Progressive Conservative Party of Nova Scotia in 1971 and became Premier of Nova Scotia in 1978. In 1990 he left provincial politics and was appointed to the Canadian Senate by Canadian Prime Minister Brian Mulroney as one of several special appointments Mulroney made under a provision in the Canadian constitution that allowed the creation of extra Senators above the ordinary limit. Murloney did this in order to pass the Goods and Services Tax through the Canadian Upper House and Buchanan obliged by voting for the unpopular measure.

Buchanan sat as a Progressive Conservative until 2004 when the party merged with the Canadian Alliance. He now sits as a Senator for the new Conservative Party of Canada.

Preceded by: Gerald A. Regan 1970-1978

Premier of Nova Scotia 1978-1990

Succeeded by: Roger Bacon 1990-1991