There are a total of 10 counties in the state of New Hampshire. Among them, Cheshire County is the oldest one (established in 1769) while Belknap County is the youngest (established in 1840). With population of 406,678, Hillsborough County is the most populated. The biggest county by land area is Coos County (4,665 km2) and the smallest is Strafford County (956 km2). Below please see all New Hampshire counties which are listed in alphabetical order.
- Belknap County, NH
- Carroll County, NH
- Cheshire County, NH
- Coos County, NH
- Grafton County, NH
- Hillsborough County, NH
- Merrimack County, NH
- Rockingham County, NH
- Strafford County, NH
- Sullivan County, NH