Hillsborough County, New Hampshire

Hillsborough County is a county in New Hampshire, United States, about 50 miles northwest of
Boston, Massachusetts. It had a population of 422,937 at the 2020 census, an estimated 433,415 by
2025, and covers 892 square miles (2,310 km2) centred near 42°55′N 71°43′W.

Manchester is the county seat, one the county shares with Nashua — New Hampshire’s
only county with two seats; Manchester’s postal code is 03101. The county holds 2 cities and
29 towns, with no unincorporated territory and no separate townships, and it runs on Eastern Time.
Its FIPS code is 33011.

Towns & Villages in Hillsborough County

Hillsborough County has 31 municipalities on record: 2 cities and 29 towns. Every acre of the
county falls inside one town or city or another — unlike counties farther south and west,
New Hampshire has no unincorporated land and no separate layer of civil townships beneath the
town itself.

Several small towns share a larger neighbor’s ZIP rather than keeping one of their own.
Mason mails through Greenville’s 03048, Deering and Windsor both mail through
Hillsborough’s 03244, and Sharon mails through Peterborough’s 03458 — none of the
four has run its own post office in decades. Several towns also carry named villages that are not
separate places on the map: Hillsborough alone has five (Hillsborough, Hillsborough Center,
Hillsborough Upper Village, Hillsborough Lower Village and Emerald Lake Village), Goffstown has
Pinardville and Grasmere, Hudson has Hudson Center, Milford’s historic centre is called Union
Square, and Lyndeborough has South Lyndeborough.

ZIP Codes

• 03101 — Manchester (also 03102–03105, 03108, 03109 and 03111 across the city)
• 03060 — Nashua (also 03061–03064)
• 03054 — Merrimack
• 03051 — Hudson
• 03110 — Bedford
• 03045 — Goffstown
• 03055 — Milford
• 03076 — Pelham
• 03031 — Amherst
• 03281 — Weare
• 03052 — Litchfield
• 03049 — Hollis
• 03458 — Peterborough (also serves Sharon)
• 03070 — New Boston
• 03244 — Hillsborough (also serves Deering and Windsor)
• 03033 — Brookline
• 03071 — New Ipswich
• 03086 — Wilton
• 03440 — Antrim
• 03057 — Mont Vernon
• 03048 — Greenville (also serves Mason)
• 03449 — Hancock
• 03047 — Greenfield
• 03082 — Lyndeborough
• 03043 — Francestown
• 03442 — Bennington
• 03084 — Temple

Geography

Hillsborough County sits in south-central New Hampshire, straddling the transition from the
rolling Merrimack River valley in the east to the Monadnock highlands in the southwest. Of its 892
square miles, 876.5 are land and 15.9 are water, about 1.8 percent — most of it the
Merrimack River, which runs north to south through Manchester, Bedford, Merrimack, Litchfield and
Nashua, and Lake Massabesic, a reservoir on the Manchester–Auburn line that supplies
Manchester’s drinking water. In the southwest corner, Pack Monadnock Mountain rises to 2,290
feet in Peterborough, the highest point in the county.

Merrimack County lies to the north, Rockingham County to the east, three Massachusetts
counties — Essex, Middlesex and Worcester — to the south, and Cheshire and Sullivan
counties to the west and northwest. Merrimack
County, Cheshire County and
Sullivan County each have
a page on this site; Rockingham County and the three Massachusetts counties on Hillsborough’s
southern edge do not, at least not under a slug this page can verify.

Demographics

Hillsborough County had a population of 422,937 at the 2020 census, and the latest estimate
puts the county near 433,415 residents. Manchester and Nashua, the two largest communities, hold
roughly 49 percent of the county’s population between them. Median household income runs
about $103,545 (2024 ACS), well above New Hampshire’s statewide figure of $96,838 (2023
ACS). Population density works out to roughly 483 people per square mile of land, the highest of
any county in northern New England.

Economy & Local Life

Manufacturing employs the most workers in the county, about 35,671 people, followed by health
care and social assistance at 33,000 and retail trade at 29,547. Fidelity Investments runs a
6,000-employee campus in Merrimack, one of the largest private employers in the state, alongside
BAE Systems’ defense-electronics operations in Nashua and Merrimack. Manchester’s Elliot
Hospital and Catholic Medical Center anchor the county’s health care sector, and Southern New
Hampshire University and Saint Anselm College, the latter straddling Manchester and Goffstown, are
the county’s largest educational employers. Peterborough is home to the MacDowell artists’
residency, founded in 1907 and still granting stays to roughly 300 writers, composers and visual
artists a year. The county’s biggest annual event is the Hillsborough County Agricultural
Fair, held in New Boston each September.

History

New Hampshire’s provincial government created Hillsborough County in 1769, one of the
colony’s five original counties, and named it for Wills Hill, 1st Earl of Hillsborough, who
served as the British Secretary of State for the Colonies. Manchester grew around the Amoskeag
Manufacturing Company, which by the mid-19th century ran the largest cotton textile mill complex
in the world on the banks of the Merrimack River; the mills employed tens of thousands of workers
before the industry collapsed after the Second World War, and the old mill yard along the river is
now a mix of offices, apartments and light industry.

Franklin Pierce, the 14th president of the United States and the only president born in New
Hampshire, was born in the town of Hillsborough in 1804. The Pierce Homestead, built the year of
his birth, is now a state-owned museum operated by the Hillsborough Historical Society.

Getting There

Interstate 93, signed the Alan B. Shepard Highway south of Manchester, crosses the county
through Manchester before continuing north as the Everett Turnpike toward Concord. Interstate 293
loops around Manchester and Bedford, and the F.E. Everett Turnpike carries Route 3 traffic through
the Nashua–Merrimack–Bedford–Manchester corridor. Route 101 runs east–west
through Milford and Wilton toward the coast, and Route 202 and Route 9 serve the western towns,
including Antrim and Hillsborough.

• Manchester — the county seat itself, in the northeast
• Nashua — about 18 miles south of Manchester
• Peterborough — about 30 miles southwest of Manchester
• Concord — about 18 miles north of Manchester, just outside the county

Manchester-Boston Regional Airport, in Manchester, is the county’s own commercial
airport and the largest in New Hampshire. The county has no active Amtrak service; the nearest
station is in Boston, roughly 50 miles south.

Frequently Asked Questions

Where is Hillsborough County located?
It sits in south-central New Hampshire, about 50 miles northwest of Boston, bordered by
Merrimack, Rockingham, Cheshire and Sullivan counties and three Massachusetts counties to the
south.

What is the population of Hillsborough County?
422,937 at the 2020 census, with an estimate near 433,415 by 2025 — the most populous
county in New Hampshire.

How big is Hillsborough County?
892 square miles (2,310 km2), of which 876.5 square miles are land.

What is the county seat of Hillsborough County?
Manchester is the county seat, one of two — the county shares the role with Nashua, the
only arrangement of its kind in New Hampshire.

How many towns and cities are in Hillsborough County?
Thirty-one: the cities of Manchester and Nashua, plus 29 towns from Amherst to Windsor.

What ZIP codes does Hillsborough County use?
27 separate codes, from 03031 in Amherst to 03458 in Peterborough, with Mason, Deering, Windsor
and Sharon sharing a neighboring town’s code.

What is Hillsborough County known for?
Manchester’s 19th-century Amoskeag cotton mills, once the largest in the world, and as the
birthplace of Franklin Pierce, the only U.S. president born in New Hampshire.

More counties in this state: Towns
and villages in New Hampshire.