Pierre Malcom Guay (March 26, 1848 – February 19, 1899) was a physician, surgeon and political figure in Quebec. He represented Lévis in the Canadian House of Commons from 1885 to 1899 as a Liberal member.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.. In 1874, he married Marie Louise Antoinette Roy.