New Hampshire Route 9 is a 109.910-mile-long (176.883 km) state highway located in southern New Hampshire. It runs across the state from west to east and is a multi-state route with Vermont and Maine, part of 1920s-era New England Interstate Route 9.

Chesterfield is a town in Cheshire County, New Hampshire, United States. The population was 3,552 at the 2020 census. It includes the villages of Spofford and West Chesterfield. Chesterfield is home to Spofford Lake, Chesterfield Gorge Natural Area, and parts of Pisgah State Park and Wantastiquet Mountain State Forest.