Hightstown is a borough in Mercer County, in the U.S. state of New Jersey. Nestled within the Raritan Valley region, Hightstown is an historic, commercial, and cultural hub of Central New Jersey, along with being a diverse outer-ring commuter suburb of New York City in the New York Metropolitan Area. As of the 2020 United States census, the borough's population was 5,900, its highest decennial count ever and an increase of 406 (+7.4%) from the 5,494 recorded at the 2010 census, which in turn reflected an increase of 278 (+5.3%) from the 5,216 counted in the 2000 census.