Hightstown is a borough in Mercer County, New Jersey, United States. 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. It was named for John and Mary Hight, who established a tavern in the area in the 1750s.