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. It was named for John and Mary Hight, who established a tavern in the area in the 1750s.
According to the United States Census Bureau, the borough had a total area of 1.242 square miles (3.218 km2), including 1.211 square miles (3.137 km2) of land and 0.031 square miles (0.081 km2) of water (2.52%).
The borough is an independent municipality surrounded entirely by East Windsor Township, making it part one of 21 pairs of "doughnut towns" in the state, where one municipality entirely surrounds another.
Hightstown is at the central-most point of New Jersey and is roughly equidistant from Philadelphia and New York City.
The record low temperature recorded in the borough was −16 °F (−27 °C) on January 28, 1935. The record high was 105 °F (41 °C) on July 9, 1936.
As of the 2010 United States Census, there were 5,494 people, 1,976 households, and 1,352 families residing in the borough. The population density was 4,536.0 per square mile (1,751.4/km2). There were 2,108 housing units at an average density of 1,740.4 per square mile (672.0/km2). The racial makeup of the borough was 69.44% (3,815) White, 8.05% (442) Black or African American, 0.56% (31) Native American, 4.08% (224) Asian, 0.15% (8) Pacific Islander, 13.56% (745) from other races, and 4.17% (229) from two or more races.