Mary MacGregor has a bachelor of science in agriculture degree and a bachelor of laws from the University of British Columbia. She was called to the bar in 1977. She practised law with Morelli Chertkow and Fulton & Company, then started the Mary MacGregor Law Corporation in 1996.

She’s a member of the Canadian Bar Association, serving on the B.C. Branch Provincial Judicial Advisory Committee, chairing the British Columbia Institute of Agrologists Conduct and Discipline Committee, and participating in the Thompson Rivers University Law School Advisory Committee. In 2013, she co-taught Real Estate Transactions at TRU Law.

Her government appointments include the British Columbia Farm Debt Review Board, the Fraser Basin Management Board, the British Columbia Fiscal Review Panel, and the British Columbia Lottery Corporation Board of Directors where she was the governance committee chair.

Her volunteer work includes the Vancouver Foundation Environmental Advisory Committee, the Canadian Cattlemen’s Association (director and co-chair of Environment and Animal Care Committee), and the British Columbia Cattlemen’s Association (director, Land Stewardship Committee, Aboriginal Affairs Committee, Treaty Negotiation Advisory Committee, Tax and Credit Committee, and Organizational Restructuring Committee). She’s also acted as a 4-H leader, and written articles for Beef in B.C. and the BC Cattlemen’s magazine. She was made a King’s Counsel in 2013.