Marion Helen Bryden (2 April 1918 – 12 February 2013) was a politician in Toronto, Ontario, Canada. She was a New Democratic Party member of the Legislative Assembly of Ontario from 1975 to 1990. 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 died in Toronto in February 2013 aged 94.