Joseph Lafontaine (November 25, 1865 – July 25, 1920) was a farmer and political figure in Quebec.
He represented Berthier in the Legislative Assembly of Quebec from 1904 to 1912 and from 1916 to 1919 as a Liberal.
He was born in Saint-Barthélémi, Canada East, the son of Amable Lafontaine and Julie Lincourt, and was educated there, at the Collège de Joliette and the Collège de l'Assomption.
Lafontaine was married twice: to Georgie Rochette in 1889 and to Juliette Mousseau in 1905.
He was mayor of Saint-Barthélémi from 1897 to 1903 and also served as warden for Berthier County.