Shrewsbury is a borough in eastern Monmouth County, in the U.S. state of New Jersey. Located within the heart of the northern Shore region, the borough is a bedroom community of New York City. As of the 2020 United States census, the borough's population was 4,184, its highest decennial count ever and an increase of 375 from the 2010 census count of 3,8…Shrewsbury is a borough in eastern Monmouth County, in the U.S. state of New Jersey. Located within the heart of the northern Shore region, the borough is a bedroom community of New York City. As of the 2020 United States census, the borough's population was 4,184, its highest decennial count ever and an increase of 375 from the 2010 census count of 3,809, which in turn reflected an increase of 219 from the 3,590 counted in the 2000 census.