Hanover is a town located along the Connecticut River in Grafton County, New Hampshire, United States. As of the 2020 census, its population was 11,870. The town is home to the Ivy League university Dartmouth College, the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, and Hanover High School. The Appalachian Trail crosses the town, connecting with a number of trails and nature preserves.