Bordentown is a city in Burlington County, New Jersey, United States. As of the 2010 United States Census, the city's population was 3,924. The population declined by 45 (-1.1%) from the 3,969 counted in the 2000 U.S. Census, which had in turn declined by 372 (-8.6%) from the 4,341 counted in the 1990 Census.