Michel-Guillaume Baby (September 15, 1834 – March 16, 1911) was a businessman and political figure in Quebec. He represented Rimouski from 1857 to 1861 and Témiscouata from 1861 to 1863 in the Legislative Assembly of the Province of Canada and Chicoutimi et Saguenay from 1874 to 1875 in the Legislative Assembly of Quebec as a Conservative. His name also appears as Michel William Baby.