Colonel Marinus Willett (July 31, 1740 – August 22, 1830) was an American military officer, politician and merchant who served as the mayor of New York City from 1807 to 1808.

Born in Jamaica, Queens, Willett underwent an apprenticeship as a cabinetmaker before enlisting in the New York Militia after the French and Indian War broke out in 1754.

[1] After the French and Indian War broke out in 1754, Willett was commissioned as a lieutenant into the New York Militia, serving in a regiment commanded by Oliver De Lancey.

[1][3][4] Serving under De Lancey, Willett participated in the Ticonderoga campaign led by James Abercrombie in July 1758 and John Bradstreet's capture of Fort Frontenac in August 1758.

[1][6] As tensions increased between Great Britain and its North American colonies, Willett aligned himself with the Patriot cause and quickly became an informal leader of the New York City branch of the Sons of Liberty.

[5][1] As noted by American historian Larry Lowenthal, his primary activities during this period consisted of inciting colonial public opinion to support the Patriot cause via rabble-rousing tactics and engaging in numerous street fights.

[9] Serving as Peter Gansevoort's aide-de-camp in the New York Highlands, Willett arrived at the now-abandoned Fort Stanwix in late-1777, renovating it and hastily establishing a garrison.

On August 6, 1777, Willett led a successful raid on the camps of Barry St. Leger and Sir John Johnson, capturing large quantities of supplies and military intelligence.

In April 1781, he was appointed as colonel of the Tryon County militia, with whom Willett secured a victory over a British-Indian force at Johnstown on October 25.

After leading an aborted attempted to capture Fort Ontario, Willett's men disbanded themselves in 1783, bringing his military career to an end.

[9] Willett's mission was successful, and a delegation of twenty-seven Muscogee leaders led by McGillivray came to the city and negotiated the 1790 Treaty of New York with Washington and United States Secretary of War Henry Knox.

[1] Having amassed a personal fortune through land speculation and the purchase of confiscated Loyalist estates after the Revolutionary War, Willett invested in these medical institutions and took an active interest in their management until his death in 1830.

In c. 1802, he paid for the neoclassicist artist John Vanderlyn to paint his wife Margaret and son Marinus Jr.[14] Over the course of his life, Willett married thrice.