Nantucket County, Massachusetts

Nantucket County is a county in Massachusetts, United States, an island about 30 miles south of
Cape Cod. It had a population of 14,255 at the 2020 census, an estimated 14,758 by 2025, and
covers 47.8 square miles (123.8 km2) of land, centred near 41°17′N 70°06′W.

Nantucket is the county seat and its only town; its postal code is 02554. The county is
coextensive with the Town of Nantucket — one municipal government covers every village on
the island, plus the outlying islands of Tuckernuck and Muskeget, and it runs on Eastern Time.
Its FIPS code is 25019.

Towns & Villages in Nantucket County

Nantucket County has 14 named places on record, all inside the single Town of Nantucket. Two
— Nantucket itself and Siasconset — are Census-designated places with their own
population counts; the rest are historic village names with no separate government or Census
tally of their own.

Tuckernuck Island and Muskeget Island sit off Nantucket’s western end, inside the town and
county but reached only by private boat; both have a handful of seasonal camps and no permanent
address system of their own. Siasconset, usually shortened to “’Sconset,” is the
only village with its own ZIP and its own historic center distinct from the main town.

ZIP Codes

• 02554 — Nantucket (covers the town center and every outlying village except Siasconset)
• 02564 — Siasconset
• 02584 — Nantucket (a business reply-mail ZIP with no resident population)

Madaket, Wauwinet, Polpis, Quidnet, Shimmo, Monomoy, Surfside, Cisco, Tom Nevers, Miacomet,
Pocomo and Squam have no post office of their own; mail there is delivered under the 02554 code.

Geography

Nantucket County is an island roughly 14 miles long and 3.5 miles wide, low and sandy, built
from glacial outwash left by the same ice sheet that shaped Cape Cod. Of its 105.3 square miles,
47.8 are land and 57.5 are water — more than half the county’s total area, split
between the Atlantic Ocean, Nantucket Sound and inland ponds and harbors, the largest being
Nantucket Harbor on the north side and the tidal Madaket Harbor to the west.

Nantucket has no land border with any other county; it sits alone in the Atlantic about 30
miles south of Cape Cod. The nearest counties are across open water: Dukes County, home of Martha’s
Vineyard, lies roughly 25 miles west, and Barnstable County, covering Cape Cod
itself, lies about 30 miles north across Nantucket Sound.

Demographics

Nantucket County had a population of 14,255 at the 2020 census, and the latest estimate puts
it near 14,758 residents. The town center CDP holds 10,166 of those year-round residents and
Siasconset another 505, together well over two-thirds of the county. The island’s summer
population swells to roughly 80,000 as seasonal homeowners and visitors arrive. Median household
income runs $116,571 (2017–2021 ACS 5-year), far above Massachusetts’s statewide
figure of $99,858 (2023 ACS). Year-round population density works out to about 298 people per
square mile of land.

Economy & Local Life

The Town of Nantucket is the island’s single largest employer, with about 670 workers
across town government, schools and public safety. Tourism and hospitality drive most private
employment — hotels, restaurants and shops that operate on a seasonal calendar tied to the
summer visitor surge — alongside construction and real estate, which serve the island’s
market for high-end second homes. Nantucket Cottage Hospital is the county’s only hospital
and a major year-round employer. Commercial bay scallop harvesting, a local trade dating back
generations, runs each winter from November through March in Nantucket Harbor. The island’s
biggest annual events are the Nantucket Wine & Food Festival in May and the Nantucket Film
Festival in June, both drawing visitors well beyond the county’s year-round population.

History

The name Nantucket comes from a Wampanoag word usually translated as “far away island.”
English settlers, led by Thomas Macy, arrived in 1659 after buying the island from Thomas Mayhew;
the town was incorporated in 1671, and the Province of Massachusetts Bay organized Nantucket as
its own county in 1695, separating it from Dukes County.

From the mid-1700s to the mid-1800s Nantucket was one of the world’s leading whaling
ports, sending ships as far as the Pacific and inspiring Herman Melville’s Moby-Dick. The
Great Fire of 1846 destroyed much of the waterfront and downtown business district. Whaling
declined sharply after the fire and the discovery of petroleum, and the island’s economy did
not fully recover until tourism took hold in the 20th century. The Nantucket Historic District,
covering nearly the entire town, was designated a National Historic Landmark District in 1966.

Getting There

No bridge or numbered highway connects Nantucket to the mainland; every visitor arrives by boat
or plane. On-island roads include Milestone Road, Polpis Road and Madaket Road, linking the town
center to the outlying villages.

• Hyannis, Cape Cod — about 30 miles north by sea
• Martha’s Vineyard — about 25 miles west by sea
• New Bedford — about 30 miles northwest by sea
• Boston — about 100 miles northwest, reached by ferry-and-bus or by air

Nantucket Memorial Airport (ACK), on the island’s southeast side, handles year-round
commercial flights to Boston and seasonal service to several other East Coast cities. The
Steamship Authority and Hy-Line Cruises run year-round car and passenger ferries from Hyannis, with
seasonal Hy-Line service also to Martha’s Vineyard. No Amtrak line reaches the island; the
historic Nantucket Railroad, which once ran from town to Siasconset, closed in 1917.

Frequently Asked Questions

Where is Nantucket County located?
It is an island in the Atlantic Ocean about 30 miles south of Cape Cod, Massachusetts, with no
land connection to the mainland.

What is the population of Nantucket County?
14,255 at the 2020 census, with a 2025 estimate near 14,758; the summer population reaches
roughly 80,000.

How big is Nantucket County?
105.3 square miles in total, of which 47.8 square miles are land and 57.5 square miles are
water.

What is the county seat of Nantucket County?
Nantucket, the town center, is the county seat — and the county’s only municipal
government, since the county and the Town of Nantucket are one and the same.

How many villages are on Nantucket?
Fourteen named places, led by the town center and Siasconset, plus twelve smaller historic
villages including Madaket, Wauwinet, Polpis and Surfside.

What ZIP codes does Nantucket County use?
02554 for the town center and most outlying villages, and 02564 for Siasconset.

Why is Nantucket both a town and a county?
The Massachusetts legislature made it a single consolidated town-county government in
1695, and it remains the only place in the state organized that way.

More counties in this state: Towns and villages in Massachusetts.