Exeter is a town in Rockingham County, New Hampshire, United States. The town's population was 14,306 at the 2010 census. Exeter was the county seat until 1997, when county offices were moved to neighboring Brentwood. Home to the Phillips Exeter Academy, a private university-preparatory school, Exeter is situated where the Exeter River feeds the tidal Squamscott River.The urban portion of the town, where 9,242 people resided at the 2010 census, is defined by the U. S. Census Bureau as the Exeter census-designated place.Exeter is named after the historic city in Devon, England.