Jacob Milborne (c. 1648-16 May 1691) was an English born clerk living in the Province of New York who was an ally, secretary and son-in-law of the rebel Jacob Leisler, served briefly as Attorney General of the province, and was executed for his part in Leisler's Rebellion.
Milborne worked as a clerk and bookkeeper for a leading New York merchant. As a fervent Puritan his religious and political views brought him into conflict with Edmund Andros, the Governor of the Province of New York, who fined and gaoled him. Milborne returned to England and successfully sued the Governor for false imprisonment.
He formed a close association with Jacob Leisler, a rich German-born businessman of liberal and Protestant views and the leader of a populist political faction known as Leislerians. When Governor Andros, now Governor of the unpopular New England Dominion, was imprisoned in Boston in 1689 for maladministration, the Leislerians took possession of Fort James in south Manhattan. The new Governor left for England and the provincial council fled to Albany. With Leisler now the de facto Governor of the province, Milborne was appointed Clerk to the Council, Attorney General and Advocate General, as well as being Leisler's Secretary and, from 1691, his son-in-law.
When a new Governor Henry Sloughter arrived with the resources to put down the rebellion, Leisler and Milborne surrendered to him. They were arrested and tried for murder and treason by a somewhat biased bench. Originally sentenced to be hanged, drawn and quartered and their estates forfeited to the crown, the two men were in the event simply hanged (Hung, but then cut down prior to death and then beheaded in front of a large crowd.) and their estates later restored to their heirs. In 1698, largely thanks to the sympathetic efforts of the then Governor, Earl of Bellomont, the bodies of the two men were disinterred and reburied at the Dutch church.