Marjolaine Boutin-Sweet (born October 3, 1955) is a Canadian anthropologist, unionist, and politician, who was first elected to the House of Commons of Canada in the 2011 election. She represented the electoral district of Hochelaga as a member of the New Democratic Party. From November 2015 to October 2019, she was also the NDP's Whip. She did not run for re-election in 2019.