Plymouth County, Massachusetts

Plymouth County is a county in Massachusetts, United States, on the South Shore about 25 miles south of Boston. It had a population of 530,819 at the 2020 census, an estimated 546,829 by 2024, and covers 659 square miles (1,710 km2) of land — 1,093 square miles in all once its bays and ponds are counted — centred near 41°59′N 70°44′W.

Plymouth is the county seat, a role it shares with Brockton, and its postal code is 02360. The county holds 27 municipalities — two governed as cities and 25 as towns — with dozens of named villages inside them, and it runs on Eastern Time. Its FIPS code is 25023.

Towns & Villages in Plymouth County

Massachusetts counties are divided completely into municipalities, so Plymouth County has no unincorporated land: every square mile belongs to one of its 27 cities and towns. Villages such as Manomet, Onset, Bryantville and Brant Rock are neighbourhoods within a town, not separate governments, though several keep their own post offices. Populations below are 2020 census counts; the ZIP shown is each municipality’s principal code.

Three separate municipalities carry the Bridgewater name — Bridgewater, East Bridgewater and West Bridgewater — and all three descend from the original 1656 town grant. Bridgewater itself is still officially a town but has governed itself as a city, with a council and manager, since a 2010 charter change; Brockton, incorporated as a city in 1881, is the only conventional city. Two more traps for map readers: the USPS spells Middleborough “Middleboro” on its postmarks, and Humarock, a beach village of Scituate, can only be reached by road through neighbouring Marshfield because the 1898 Portland Gale rerouted the North River’s mouth.

ZIP Codes

Each town’s principal ZIP appears in the table above. Beyond those 27, the county has a layer of village and secondary codes, the busiest of which are listed here.

• 02302 — Brockton’s east side (02303, 02304 and 02305 are Brockton PO box codes)
• 02345 — Manomet, and 02360’s coastal Plymouth villages south of downtown
• 02538 — East Wareham; 02558 — Onset; 02576 — West Wareham
• 02327 — Bryantville and 02350 — Monponsett, both village codes in Pembroke and Halifax
• 02020 — Brant Rock, 02041 — Green Harbor and 02051 — Marshfield Hills, all in Marshfield
• 02047 — Humarock (Scituate) and 02066’s satellites 02055 (Minot) and 02060 (North Scituate)
• 02337 — Elmwood (East Bridgewater); 02366 — South Carver; 02355 — North Carver
• 02018 — Accord, a village post office on the Hingham–Norwell line

Norwell, Rockland, Whitman and most inland towns manage with a single code, while Plymouth — the largest town by land in Massachusetts — spreads across 02360 plus village codes 02345, 02361, 02362 and 02381 (White Horse Beach). Codes such as 02331 (Duxbury) and 02362 (Plymouth) serve post office boxes only.

Geography

Plymouth County occupies the coastal plain between Boston Harbor and the Cape Cod Canal. Of its 1,093 square miles, 659 are land and 434 are water — a 40 percent water share, the product of a long Atlantic shoreline on Massachusetts Bay, Cape Cod Bay and Buzzards Bay plus hundreds of kettle ponds left by the last glaciation. The interior is sandy pine barrens and cranberry country; Myles Standish State Forest, spread across Plymouth and Carver, is one of the largest public reserves in Massachusetts at roughly 12,400 acres. The Taunton River rises from the Bridgewaters’ wetlands, and the North River separates Marshfield from Scituate and Norwell.

Norfolk County lies to the north and northwest, toward Quincy and Boston. Bristol County borders the county on the west and southwest, from Easton down to New Bedford. To the southeast, Barnstable County begins at the Bourne town line by the Cape Cod Canal, beyond Wareham.

Demographics

Plymouth County counted 530,819 residents in 2020 and an estimated 546,829 by 2024, making it the fifth most populous county in Massachusetts. Brockton and Plymouth are the two largest communities; together they hold nearly a third of the county’s people. Density works out to about 805 residents per square mile of land, though the spread is extreme — Brockton packs over 4,900 per square mile while rural Rochester and Plympton stay under 175. Median household income was $114,201 in 2024, ahead of the Massachusetts statewide figure of $103,960, with the coastal towns of Hingham, Norwell and Duxbury ranking among the wealthiest in the region.

Economy & Local Life

Health care and social assistance is the county’s biggest employer, with about 46,932 workers, followed by retail trade at 31,311 and educational services at 26,477. Brockton anchors the hospital sector with Signature Healthcare Brockton Hospital and Good Samaritan Medical Center; Beth Israel Deaconess Hospital-Plymouth serves the coastal towns. Bridgewater State University, with roughly 9,000 students, is the county’s largest campus. The signature industry is cranberries: bogs concentrated in Carver, Wareham, Plympton and Middleborough make the county the historic centre of Massachusetts cranberry growing, and grower cooperative Ocean Spray keeps its headquarters on the Lakeville–Middleborough line. The biggest annual event is America’s Hometown Thanksgiving Celebration in Plymouth each November, a parade weekend built around the town’s Mayflower story.

History

This is Wampanoag homeland, and the shore where the Mayflower’s passengers landed in December 1620 to found Plymouth Colony, the first permanent English settlement in New England. King Philip’s War (1675–76), the devastating conflict between colonists and the Wampanoag leader Metacom, began and ended within the old colony’s bounds; Metacom was killed in August 1676 and the war broke Native political power in the region.

Plymouth Colony’s General Court created the county on 2 June 1685, making it one of the oldest counties in the United States, and it kept its name and bounds when the colony was absorbed into the Province of Massachusetts Bay in 1691. Two centuries later Brockton grew into “Shoe City”, at its peak producing more shoes than any place in the country and supplying a large share of Union army footwear during the Civil War. Like most Massachusetts counties, Plymouth County retains its government — commissioners, registry of deeds and sheriff — where many neighbouring counties were abolished in the 1990s.

Getting There

Route 3 is the county’s spine, running from the Braintree split south through Rockland, Hanover, Pembroke, Duxbury, Kingston and Plymouth to the Sagamore Bridge. Route 24 carries Boston-bound traffic through the Brockton area, Interstate 495 cuts across Middleborough and Wareham to end at Interstate 195, which continues west through Marion and Mattapoisett toward New Bedford and Providence. US 44 links Plymouth with Middleborough and Taunton.

• Boston — about 25 miles north of Brockton
• Providence — about 35 miles west of Middleborough
• New Bedford — about 10 miles southwest of Mattapoisett
• Cape Cod (Bourne) — immediately southeast of Wareham, across the canal

Boston Logan International Airport, roughly 40 miles north of Plymouth, is the nearest major airport; T.F. Green in Rhode Island serves the county’s southwest corner. No Amtrak line enters the county — the nearest stations are Boston’s South Station and Providence — but three MBTA commuter rail lines do: Greenbush to Scituate, the Kingston line via Halifax, and the Fall River/New Bedford line with stops in Brockton, Bridgewater and Middleborough.

Frequently Asked Questions

Where is Plymouth County located?
On the South Shore of Massachusetts, between Boston Harbor and the Cape Cod Canal, bordered by Norfolk, Bristol and Barnstable counties.

What is the population of Plymouth County?
530,819 at the 2020 census, with a 2024 estimate of 546,829.

How big is Plymouth County?
1,093 square miles in total, of which 659 square miles (1,710 km2) are land and 434 are water.

What is the county seat of Plymouth County?
Plymouth and Brockton share the role; the courts and registry of deeds sit in Plymouth and Brockton is the larger city.

How many towns are in Plymouth County?
27 municipalities: Brockton and Bridgewater run city governments, and the other 25 — from Plymouth down to tiny Plympton — are towns.

What ZIP codes does Plymouth County use?
Around 60 codes in the 020–027 ranges, from 02301/02302 in Brockton and 02360 in Plymouth to village codes like 02558 (Onset) and 02047 (Humarock).

What is Plymouth County known for?
The Mayflower landing and Plymouth Rock, America’s Hometown Thanksgiving Celebration, cranberry bogs, and Brockton’s boxing and shoemaking heritage.

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