Marinus Willett (July 31, 1740 – August 22, 1830) was an American soldier and political leader from New York. He was characterized by historian Mark M. Boatner as "one of the truly outstanding American leaders of the Revolution."
Willett was born in Jamaica, New York, on Long Island, the son of Edward Willett a school teacher and tavern operator.
Marinus Willett served in the militia during the French and Indian War. He received a commission as 2nd lieutenant in a New York regiment under the command of Oliver DeLancey Sr. which took part in General James Abercrombie's expedition to Fort Ticonderoga in 1758. His regiment was part of John Bradstreet's army in the Battle of Fort Frontenac. He became ill and stayed at Fort Stanwix until he recovered.
Tradition is between the wars he worked as a cabinetmaker.