Amherst is a town in Hillsborough County in the state of New Hampshire, United States. The population was 11,753 at the 2020 census. Amherst is home to Ponemah Bog Wildlife Sanctuary, Hodgman State Forest, the Joe English Reservation and Baboosic Lake.

Hillsborough County is the most populous county in the U.S. state of New Hampshire. As of the 2020 census, the population was 422,937, almost one-third the population of the entire state. Its county seats are Manchester and Nashua, the state's two biggest cities. Hillsborough is northern New England's most populous county as well as its most densely populated.