Antoine Laumet, dit de La Mothe, sieur de Cadillac (March 5, 1658-October 15, 1730), a French explorer, was a colourful figure in the history of New France. He gave himself the name and title de La Mothe, sieur de Cadillac and founded the city of Detroit.

Born at Les Laumets, he arrived in 1683 at Port-Royal, Acadia, where Governor Frontenac made him a lieutenant and later a captain. He moved to Quebec in 1691 and was commissioned in the Troupes de la Marine.

In 1694 he was named commander of Fort Michillimakinac in Michigan, where he stayed until 1697. He convinced the comte de Pontchartrain to found a colony at Detroit, which he commanded 1701-1710. Originally, the settlement was called Fort Pontchartrain du Détroit. He was removed from that post when it became apparent he was using it for his own gain. His lieutenant, Alphonse de Tonty, became the new fort commandant.

He was then named governor of Louisiana, but returned to France in 1717, where he died at Castelsarrasin. His former house is in Montreal. It is now converted into a McDonald's restaurant.

Cadillac, Michigan, a town in Northern Michigan is named for him.