Antoine-Gaspard Couillard (February 16, 1789 – June 12, 1847) was a seigneur, physician and political figure in Lower Canada.
He articled in law with Alexandre-André-Victor Chaussegros de Léry, but then decided to become a doctor, studying with Samuel Holmes and René-Joseph Kimber.
He completed his studies at the University of Pennsylvania and then returned to Lower Canada in 1811 and was authorized to practice medicine.
He was a justice of the peace and was named to the Legislative Council of Lower Canada in 1832.
His daughter Catherine Charlotte-Éliza married Alexandre-René Chaussegros de Léry, who later served in the Canadian Senate.