Hightstown is a borough in Mercer County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 5,494, reflecting an increase of 278 (+5.3%) from the 5,216 counted in the 2000 Census, which had in turn increased by 90 (+1.8%) from the 5,126 counted in the 1990 Census.
Hightstown was incorporated as a borough by an Act of the New Jersey Legislature on March 5, 1853, within portions of East Windsor Township. The borough became fully independent c. 1894. Additional portions of East Windsor Township were annexed in 1913, 1915 and 1927.