Tom Manley (born 1960 in Berwick, Ontario) is a politician in Ontario, Canada. He was one of three co-Deputy Leaders of the Green Party of Canada until 2005, and was considered a leading candidate to be its next leader. On Friday, September 23 2005, Manley resigned from the Green Party to join the Liberal Party of Canada. He ran in the 39th General Election in the Stormont—Dundas—South Glengarry riding in Ontario, losing to Conservative Guy Lauzon with a margin of over 14,000 votes.