Gilbert Livingston (December 17, 1742 – September 14, 1806) was a lawyer who, in 1788, served as a delegate to the Poughkeepsie Convention where, despite having arrived at the convention as an Anti-Federalist, he ultimately voted to ratify the United States Constitution. Both before and after that ratification convention, he served in the New York Assembly, representing Dutchess County. Livingston had also been a member of the New York Provincial Congress.
Gilbert was one of the thirteen children of Henry Livingston, Sr. and Susanna Conklin Livingston. Gilbert's father, Henry, was County Clerk in Dutchess County, as well as a legislator in colonial New York. They were a middle-class family, and were members of the Dutch Reformed Church. They inhabited a less affluent branch of the prominent Livingston family of New York. One of Gilbert's great-grandfathers was the wealthy New York colonial official Robert Livingston the Elder, and one of Gilbert's siblings was the poet Henry Livingston, Jr.
Gilbert was born and grew up near Poughkeepsie, and went to school in Fishkill, New York. He then went to King's College, which was the colonial-era name of Columbia College, Columbia University, but left early (in 1757) due to a smallpox epidemic.
Livingston practiced law, owned a small farm with a few tenants, and ran a store in Poughkeepsie with the brother of prominent politician Melancton Smith. In 1763, he married Catherine Crannell, the daughter of law partner Bartholomew Crannell. Gilbert and Catherine would have one child, Sarah, who later married another law partner of Gilbert: the famous jurist Smith Thompson. The renowned jurist James Kent was also one of Livingston's law partners.