Counties of New Hampshire
Coös Grafton Carroll Belknap Strafford Merrimack Sullivan Cheshire Hillsborough Rockingham
Location	State of New Hampshire
Number	10
Populations	31,504 (Coös) – 426,594 (Hillsborough)
Areas	369 square miles (960 km2) (Strafford) – 1,801 square miles (4,660 km2) (Coös)
Government	County government
Subdivisions	cities, towns, townships, villages, unincorporated territories, census designated place

There are ten counties in the U.S. state of New Hampshire. Five of the counties were created in 1769, when New Hampshire was still an English colony and not a state, during the first subdivision of the state into counties. The last counties created were Belknap County and Carroll County, in 1840.

The majority of New Hampshire's counties were named for prominent British or American people or geographic locations and features. Only one county's name originates in a Native American language: Coös County, named for an Algonquian word meaning "small pines".

The counties tend to be smaller in land area towards the southern end of the state, where New Hampshire population is concentrated, and larger in land area in the less populous north.^[1][2]

The FIPS county code is the five-digit Federal Information Processing Standard (FIPS) code which uniquely identifies counties and county equivalents in the United States. The three-digit number is unique to each individual county within a state, but to be unique within the entire United States, it must be prefixed by the state code. This means that, for example, while Belknap County, New Hampshire is 001, Addison County, Vermont and Alachua County, Florida are also 001. To uniquely identify Belknap County, New Hampshire, one must use the state code of 33 plus the county code of 001; therefore, the unique nationwide identifier for Belknap County, New Hampshire is 33001. The links in the column FIPS County Code are to the Census Bureau Info page for that county.^[3]

List

County	FIPS code [3]	County seat [4]	Est. [4]	Formed from [5]	Etymology [2]	Population [6]	Area [4][6]	Map
Belknap County	001	Laconia	1840	Parts of Merrimack County and Strafford County.	Jeremy Belknap (1744–1798), early New Hampshire historian.	64,781	401 sq mi (1,039 km2)
Carroll County	003	Ossipee	1840	Part of Strafford County.	Charles Carroll of Carrollton (1737–1832), the last surviving signatory of the United States Declaration of Independence.	52,199	934 sq mi (2,419 km2)
Cheshire County	005	Keene	1769	One of five original counties.	English county of Cheshire.	77,350	708 sq mi (1,834 km2)
Coös County	007	Lancaster	1803	Part of Grafton County.	An Algonquian word meaning "small pines".	31,504	1,801 sq mi (4,665 km2)
Grafton County	009	Haverhill	1769	One of five original counties.	Augustus Henry Fitzroy, 3rd Duke of Grafton (1735–1811), a Prime Minister of Great Britain (1768–1770).	91,126	1,714 sq mi (4,439 km2)
Hillsborough County	011	Manchester and Nashua	1769	One of five original counties.	Wills Hill, 1st Marquess of Downshire (1718–1793), known in America as the Earl of Hillsborough, who served as the first Secretary of State for the Colonies.	426,594	876 sq mi (2,269 km2)
Merrimack County	013	Concord	1823	Parts of Hillsborough County and Rockingham County.	The Merrimack River.	156,020	934 sq mi (2,419 km2)
Rockingham County	015	Brentwood	1769	One of five original counties.	Charles Watson-Wentworth, 2nd Marquess of Rockingham (1730–1782), a two-time Prime Minister of Great Britain (1765–1766, 1782).	319,424	695 sq mi (1,800 km2)
Strafford County	017	Dover	1769	One of five original counties.	William Wentworth, 2nd Earl of Strafford (1626–1695), an English noble who owned colonial lands.	132,275	369 sq mi (956 km2)
Sullivan County	019	Newport	1827	Part of Cheshire County.	John Sullivan (1740–1795), the third and fifth governor of New Hampshire (1786–1788, 1789–1790).	43,958	537 sq mi (1,391 km2)