The Honourable Stewart Donald McInnes (born July 24 1937) is a lawyer, arbitrator and former politician.

From 1961 to 1999, McInnes was a senior partner in the Halifax, Nova Scotia law firm of McInnes, Cooper and appeared before the Supreme Court of Nova Scotia, the Federal Court of Canada and the Supreme Court of Canada. He also served as the president of the Nova Scotia branch of the Canadian Bar Association from 1983 to 1984.

In the 1984 general election he was elected to the Canadian House of Commons as the Progressive Conservative Member of Parliament for Halifax defeating Trudeau Cabinet minister and former Premier of Nova Scotia Gerald Regan.

In 1985, he was appointed to Brian Mulroney's cabinet as Minister of Supply and Services . From 1986 until 1988 he concurrently held the positions of Minister of Public Works and Minister responsible for the Canada Mortgage and Housing Corporation.

McInnes was defeated in the 1988 federal election by Liberal Mary Clancy due, in part, to the unpopularity of the Canada-US Free Trade Agreement in Atlantic Canada and returned to his law practice full time.

He is a certified arbitratory and mediator and has focussed professionally in those areas since leaving politics. McInnes served as director of the Arbitration and Mediation Institute of Canada from 1993 to 1995, and served from 1993 to 1994 as director of the Atlantic Arbitration and Mediation Institute. In 1996, he was on the International Mediation Centre’s advisory board, and in 1999 he was a panel member of the Canadian Foundation for Dispute Resolution. He has lectured and written extensively on the topic of mediation and arbitration.

Since leaving the House of Commons, McInnes has remained active in politics as a major fundraiser for the Progressive Conservative Party of Nova Scotia.