Bordentown is a city in Burlington County, in the U.S. state of New Jersey. As of the 2020 United States census, the city's population was 3,993, an increase of 69 from the 2010 census count of 3,924, which in turn reflected a decline of 45 from the 3,969 counted in the 2000 census. Bordentown is located at the confluence of the Delaware River, Blacks Creek, and Crosswicks Creek. The latter is the border between Burlington and Mercer counties.