Bound Brook is a borough in Somerset County, in the U.S. state of New Jersey, located along the Raritan River. As of the 2020 United States census, the borough's population was 11,988, an increase of 1,586 from the 2010 census count of 10,402, which in turn reflected an increase of 247 from the 10,155 counted in the 2000 census,. Bound Brook was originally incorporated as a town by an act of the New Jersey Legislature on March 24, 1869, within portions of Bridgewater Township.