Pierre Malcom Guay (March 26, 1848 – February 19, 1899) was a physician, surgeon and political figure in Quebec.

He was born in Saint-Romuald d'Etchemin, Canada East, the son of François Xavier Guay and Marie Adelaide Côté.

Guay was educated at the Séminaire de Quebec and the Université Laval, where he received a M.D.

He was first elected to the House of Commons in an 1885 by-election held after Isidore-Noël Belleau was unseated following an appeal.

Belleau unseated on a judgement of the Supreme Court, 16 March 1885 This article about a Quebec Member of Parliament from the Liberal Party of Canada is a stub.