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There are 24 Sussex County NJ towns: 15 townships, 8 boroughs and one town, Newton, which is also the county seat. That count comes straight from the Sussex County Facts sheet published by the Sussex County Clerk, and it is the list our team uses every time we cover news, events and food across the county.
If you are asking where Sussex County NJ is: it is the northernmost county in New Jersey, in the northwest corner of the state. It is the only New Jersey county that borders both New York and Pennsylvania, with the Delaware River forming its western edge. Below is every municipality, what it is known for and the unincorporated communities you will hear locals name.
Where Is Sussex County NJ?
Sussex County sits in the far northwest of New Jersey, in the region often called the Skylands. New York is to the north, Pennsylvania is across the Delaware River to the west, and within New Jersey the county borders Warren, Morris and Passaic counties. Kittatinny Mountain, part of the Appalachian chain, runs along the western side of the county.
- County seat: Newton, home of the Sussex County Courthouse at High and Spring Streets.
- Population: 144,221 at the 2020 Census, with a U.S. Census Bureau estimate of 148,063 as of July 1, 2025, per Census QuickFacts.
- Land area: about 518.66 square miles, per the 2020 Census.
- Highest point: High Point, 1,803 feet, the highest elevation in New Jersey, per the county facts sheet.
- Largest body of water: Lake Hopatcong, per the county facts sheet.
- Formed: 1753, from land that had been part of Morris County. Warren County was later split off from Sussex in 1824.
What Towns Are in Sussex County NJ? The Quick List
Boroughs (8): Andover Borough, Branchville, Franklin, Hamburg, Hopatcong, Ogdensburg, Stanhope, Sussex.
Townships (15): Andover Township, Byram, Frankford, Fredon, Green, Hampton, Hardyston, Lafayette, Montague, Sandyston, Sparta, Stillwater, Vernon, Walpack, Wantage.
Town (1): Newton.
You may see “15 townships and 9 boroughs” elsewhere, but the county lists Newton as a town, which is its own form of government in New Jersey. Note that Andover has two separate municipalities: Andover Borough and Andover Township.
All 24 Sussex County Municipalities, A to Z
Andover Borough
Type: Borough. A small borough of about 1.4 square miles on U.S. Route 206, incorporated in 1904. It is a separate municipality from the larger Andover Township that surrounds it.
Andover Township
Type: Township. A largely rural township of about 21 square miles and home to Kittatinny Valley State Park and Lake Aeroflex. Communities: Brighton, Pinkneyville, Springdale and Whitehall.
Branchville
Type: Borough. At about 0.56 square miles, Branchville has the smallest land area of any Sussex County municipality, per the county facts sheet. Route 206 runs through the borough on its way north toward Stokes State Forest.
Byram Township
Type: Township. Byram, in the southeast of the county, includes Cranberry Lake and is home to the Wild West City theme park. Communities: Byram Center, plus a small part of the Lake Mohawk census area (the lake itself is in Sparta).
Frankford Township
Type: Township. Frankford is best known for Augusta, the community that is home to the Sussex County Fairgrounds and Skylands Stadium. Culver Lake is also in the area. Communities: Augusta and Ross Corner.
Franklin
Type: Borough. Franklin is famous for its zinc mining history and its fluorescent minerals, and it promotes itself as the Fluorescent Mineral Capital of the World. Our guide to things to do in Franklin NJ covers the mineral attractions.
Fredon Township
Type: Township. A rural, mostly residential township of about 18 square miles just west of Newton, incorporated in 1904.
Green Township
Type: Township. A farm country township in the southern part of the county, incorporated in 1824, with more than 500 acres of preserved farmland on the county’s records.
Hamburg
Type: Borough. A compact borough of about 1.2 square miles in the Vernon Valley area along the Wallkill River, incorporated in 1920. It is also home to the historic Gingerbread Castle.
Hampton Township
Type: Township. A township of about 25 square miles bordering Newton, incorporated in 1864. Communities: part of Crandon Lakes, which it shares with Stillwater.
Hardyston Township
Type: Township. One of the county’s oldest municipalities, dating to 1762, Hardyston wraps around Franklin and Hamburg and includes the Crystal Springs resort area. Communities: Stockholm.
Hopatcong
Type: Borough. Hopatcong sits on the shores of Lake Hopatcong, the largest body of water in the county. The lake is shared with Morris County towns on its other shores. See our where to eat in Hopatcong NJ guide.
Lafayette Township
Type: Township. A farming township in the center of the county, incorporated in 1845, with nearly 950 acres of preserved farmland on the county’s records.
Montague Township
Type: Township. Montague, in the far northern tip of New Jersey, is home to High Point, the highest elevation in the state at 1,803 feet, inside High Point State Park. The township meets New York and Pennsylvania along the Delaware River. Our High Point State Park fall foliage guide has visiting tips.
Newton
Type: Town. Newton is the Sussex County seat and the county’s government and commercial center, with the Sussex County Courthouse, the Newton Town Green and the Spring Street business district. Sussex County Community College is also in Newton.
Ogdensburg
Type: Borough. Ogdensburg is home to the Sterling Hill Mine, now a mining museum. The county facts sheet lists the mine, at 2,100 feet below sea level, as the lowest point in Sussex County.
Sandyston Township
Type: Township. A heavily wooded township of about 41 square miles along the Delaware River, home to much of Stokes State Forest and part of the Delaware Water Gap National Recreation Area. Communities: Layton.
Sparta Township
Type: Township. Sparta is one of the county’s most populous municipalities and is known for Lake Mohawk, a private lake community with a shopping and dining district around its boardwalk. Browse our Sparta and Lake Mohawk dining guide. Communities: Lake Mohawk.
Stanhope
Type: Borough. A small borough of about 1.7 square miles on the county’s southern border with Morris County, along the Musconetcong River, incorporated in 1904.
Stillwater Township
Type: Township. Stillwater is home to Swartswood Lake and Swartswood State Park. Communities: Swartswood and part of Crandon Lakes.
Sussex
Type: Borough. Sussex Borough, at about 0.75 square miles, is a small downtown in the northern part of the county. It was known as Deckertown before taking the name Sussex, and it was incorporated in 1891.
Vernon Township
Type: Township. Vernon, in the northeast corner of the county, was the most populous municipality in Sussex County at the 2010 Census. It is home to the Mountain Creek ski area, and the Appalachian Trail crosses the township. Communities: Glenwood, Highland Lakes, McAfee, Vernon Center, Vernon Valley and part of Upper Greenwood Lake.
Walpack Township
Type: Township. Walpack, along the Delaware River, lies almost entirely within the Delaware Water Gap National Recreation Area. It had just 16 residents at the 2010 Census, the fewest in the county. Communities: Walpack Center.
Wantage Township
Type: Township. Wantage has the largest land area of any Sussex County municipality on the county facts sheet, at about 68 square miles, and the most preserved farmland. It is home to Space Farms Zoo and Museum. Communities: Beemerville and Quarryville.
Know Before You Explore
- Mailing addresses do not always match town lines. Many places use a post office name from a neighboring town, so a “Branchville” or “Sussex” address can sit in a surrounding township. Check the municipality if you need town services.
- Unincorporated communities are not separate towns. Augusta, Highland Lakes, Layton, Swartswood and Lake Mohawk have their own names and identities but are governed by the township they sit in.
- Distances are longer than they look. The county covers more than 500 square miles of land, much of it state forest, parkland and farmland, so plan driving time between the north and south ends.
- Lake communities can be private. Several well known lakes, including Lake Mohawk, are private, so check access before you go.
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Frequently Asked Questions
How many towns are in Sussex County NJ?
There are 24 municipalities: 15 townships, 8 boroughs and 1 town (Newton), per the Sussex County Clerk’s county facts sheet.
What is the county seat of Sussex County NJ?
Newton is the county seat. County offices are at One Spring Street in Newton.
Where is Sussex County NJ located?
In the northwest corner of New Jersey. It borders New York to the north and Pennsylvania across the Delaware River to the west, and Warren, Morris and Passaic counties within New Jersey.
What is the largest town in Sussex County NJ?
By population, Vernon Township was the largest at the 2010 Census. By land area, Wantage Township is the largest on the county facts sheet, with Vernon close behind.
Is Lake Hopatcong in Sussex County or Morris County?
Both. The Borough of Hopatcong covers the Sussex County shoreline, and the rest of the lake borders Morris County towns.
Primary sources for this guide: Sussex County Facts, Sussex County Clerk; Sussex County municipality listing, sussex.nj.us; U.S. Census Bureau QuickFacts, Sussex County, NJ. Background history: Sussex County, New Jersey and List of municipalities in Sussex County on Wikipedia.
Featured photo: the 1847 Sussex County Courthouse in Newton. Photo by Zeete via Wikimedia Commons, CC BY-SA 4.0.
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