Louis Guy (June 27, 1768 – February 17, 1850) was a notary and political figure in Lower Canada.
Guy studied to be a land surveyor and learned English at the College of New Jersey in Princeton.
On his return, he articled in law with Joseph Papineau, qualified as a notary in 1801 and set up practice in Montreal.
Although he was opposed to the use of force by the rebels during the Lower Canada Rebellion, he viewed the imposition of martial law as a measure only to be taken as a last resort.
His brother Étienne served as a member of the legislative assembly.