Joseph Lafontaine (4 April 1885 - 14 December 1965) was a merchant and political figure in Quebec. He represented Mégantic—Frontenac and then Mégantic in the House of Commons of Canada as a Liberal member from 1940 to 1958.
He was born in St-Calixte de Somerset, Quebec, the son of Grégoire Lafontaine and Aurélie Tourigny, and was educated in Arthabaska. In 1906, he married Marie-Louise Boisvert. Lafontaine was an unsuccessful candidate for a seat in the Quebec assembly in 1935. He lived in Thetford Mines.