Englishtown is a rapidly growing borough in western Monmouth County, in the U.S. state of New Jersey. The community is located within the Raritan Valley region. As of the 2020 United States census, the borough's population was 2,346, its highest decennial count ever and an increase of 499 from the 2010 census count of 1,847, which in turn reflected an i…Englishtown is a rapidly growing borough in western Monmouth County, in the U.S. state of New Jersey. The community is located within the Raritan Valley region. As of the 2020 United States census, the borough's population was 2,346, its highest decennial count ever and an increase of 499 from the 2010 census count of 1,847, which in turn reflected an increase of 83 from the 1,764 counted in the 2000 census.