Lawrence is a city in Essex County, Massachusetts, United States, on the Merrimack River. As of the 2010 census, the city had a population of 76,377, which had risen to an estimated 78,197 as of 2014. Surrounding communities include Methuen to the north, Andover to the southwest, and North Andover to the southeast. Lawrence and Salem are the county seats of Essex County. Lawrence is part of the Merrimack Valley.