Morristown is a city in and the county seat of Hamblen County, Tennessee, United States. The population was 29,137 at the 2010 United States Census. It is the principal city of the Morristown, Tennessee Metropolitan Statistical Area, which encompasses all of Grainger, Hamblen, and Jefferson counties. The Morristown metropolitan area is also a part of the Knoxville-Sevierville-La Follette Combined Statistical Area. According to the 2010 Census, the city has a total area of 20.9 square miles (54.1 km²).Some of the area is covered with water, specifically Cherokee Lake, an artificial reservoir built by the Tennessee Valley Authority in the 1940s.