John B. LaBossiere (January 1, 1935 – January 11, 2006)^[1][2] was a Canadian politician who was leader of the New Brunswick New Democratic Party from 1976 to 1980.^[3] The party's first francophone leader, he was noted for making inroads into the province's Acadian community, taking the party to a then-record level of support in the 1978 provincial election.^[4] He was also an early advocate of environmentalism in the province, building his campaign on opposition to aerial spraying and to the proposed Point Lepreau Nuclear Generating Station.^[4] He resigned as leader in July 1980, following a dispute with the party's executive committee, complaining that the NDP had drifted from its socialist principles.^[5][6]

A teacher by profession,^[4] he taught at the Bonar Law High School in Rexton, New Brunswick, and was married to Ferne (Fearon) LaBossiere, a native of Tide Head, New Brunswick. He was a graduate of the University of New Brunswick. LaBossiere was active in many community organizations and deeply committed to many causes. He was elected and served on the Rexton-Richibucto school board for many years.^{[citation needed]}

He ran for the Legislative Assembly of New Brunswick in the 1978 and 1995 elections.^{[citation needed]}