Kingsport is a city in Sullivan and Hawkins counties in the U.S. state of Tennessee; most of the city is in Sullivan County. As of the 2010 census the population was 48,205; as of 2016 the estimated population was 52,806.Kingsport is the largest city in the Kingsport–Bristol–Bristol, TN-VA Metropolitan Statistical Area, which had a population of 309,544 as of 2010. The Metropolitan Statistical Area is a component of the Johnson City–Kingsport–Bristol, TN-VA Combined Statistical Area – commonly known as the "Tri-Cities" region. Census data from 2006–2008 for the Tri-Cities Combined Statistical Area estimates a population of 496,454.Kingsport is commonly included in what is known as the Mountain Empire, which spans a portion of southwest Virginia and the mountainous counties in eastern Tennessee. The name "Kingsport" is a simplification of "King's Port", originally referring to the area on the Holston River known as King's Boat Yard, the head of navigation for the Tennessee Valley.