Marion Helen Bryden (2 April 1918 – 12 February 2013) was a politician in Toronto, Ontario, Canada.
Prior to becoming a politician, she was actively involved in the Co-operative Commonwealth Federation and helped found the Ontario New Democratic Party in 1961.
She was a member of the Canadian Council of Social Development, the Elizabeth Fry Society, and the Federation of Ontario Naturalists.
The Beaches—Woodbine riding, now renamed as Beaches—East York, remained in NDP hands with Bryden being succeeded by Frances Lankin and then Michael Prue.
From 1985 to 1990, Bryden served as her party's critic for Colleges and Universities, the Solicitor-General, Correctional Services, Seniors' Issues, Revenue and Transport.