Raritan is a borough in Somerset County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 7,835, its highest decennial census count ever and an increase of 954 from the 2010 census count of 6,881, which in turn had reflected an increase of 543 from the 6,338 counted at the 2000 census. The borough's name is derived from the Raritans, a Native American group of Lenape.