William Duer (March 18, 1743 – May 7, 1799)[1] was a British-born American jurist, developer, and financial speculator from New York City.

In 1792, following his involvement in one of the nation's first financial panics, Duer went bankrupt and was confined to debtors' prison, where he died seven years later.

[1] He was the son of John Duer, a planter in Antigua in the West Indies, who kept a villa in Devon, and Frances Frye.

She was the daughter of Sir Frederick Frye, who held a command in the West Indies, where she met and married Duer.

He traveled to New York State for the first time in 1768, to arrange for a regular and constant supply of lumber for his plantations in Antigua and Dominica.

On a previous trip to the area, Duer had purchased tracts of land on the upper Hudson River near Albany.

The area, known as Fort Miller, served both as Duer's first residence and as the site of his early financial ventures.

[1] Duer was originally a moderate Whig, somewhat reluctant to become involved in active resistance to the British government.

[6] In 1779, Duer returned to private business, in partnership with John Holker, the French commercial agent.