Map of New Jersey Counties

New Jersey has 21 counties, and the Ultimaps map shows all 21. The count has not changed since 1857, when the state created Union County from part of Essex County. County and municipal boundaries have been adjusted since then, but no new county has been formed. The counties vary a lot in population. Bergen County had 978,641 residents in July 2024 and Salem County had 65,874, according to U.S. Census Bureau estimates, and all 21 together had 9,500,851. For comparison, neighboring Pennsylvania has 67 counties, New York has 62 and Delaware has 3. Trenton, the state capital, is the seat of Mercer County.

Burlington County is the largest county in New Jersey by land area, with 799.3 square miles (2,070 km²) according to the U.S. Census Bureau's 2026 Gazetteer Files. It borders the Delaware River opposite Pennsylvania and includes part of the Pine Barrens and Wharton State Forest. Its county seat is Mount Holly. Ocean County is larger if you count water. Ocean has 628.3 square miles of land and 286.5 square miles of water, including Barnegat Bay, for a total of 914.8 square miles (2,369 km²). Burlington has only 21.1 square miles of water, so its total is about 820 square miles (2,125 km²). Both counties are far larger than Hudson, the smallest, at 46.2 square miles of land.

Bergen County is the most populated county in New Jersey, with 978,641 residents in July 2024 according to U.S. Census Bureau estimates. It occupies the state's northeast corner on the Hudson River, where the George Washington Bridge connects it to Manhattan, and its county seat is Hackensack. MetLife Stadium and part of the New Jersey Meadowlands are also in Bergen. Middlesex County is second with 890,119 people, and Essex County, home to Newark, the state's largest city, is third with 881,527. Bergen grew by 24,930 residents between the 2020 and 2024 estimates. Middlesex added slightly more, 28,659, so the gap between the two counties narrowed.

Hudson County is the smallest county in New Jersey by area, with 46.2 square miles (120 km²) of land, or 62.4 square miles (162 km²) including water, per the U.S. Census Bureau's 2026 Gazetteer Files. Hudson is not small in population. Its 736,185 residents (2024 Census Bureau estimate) rank fourth of 21. They live in places such as Jersey City, the county seat, and Hoboken, across the Hudson River from Manhattan, at roughly 15,900 people per square mile of land. Measured by population, the smallest county is Salem County, along the Delaware River, with 65,874 residents (2024) on 331.9 square miles of land, or about 200 per square mile.

Trenton, the capital of New Jersey, is in Mercer County and is also the county seat. Trenton became the permanent state capital in 1790, 48 years before the legislature created Mercer County in 1838 from parts of Burlington, Hunterdon, Middlesex and Somerset counties. Mercer had 392,138 residents in July 2024 according to U.S. Census Bureau estimates, 12th of the 21 counties. The city lies on the Delaware River, across from Pennsylvania. Mercer County also includes Princeton, with Princeton University and Princeton Battlefield State Park.

New Jersey's oldest counties are Bergen, Essex, Middlesex and Monmouth, all formed in 1683 in the colony of East Jersey. Gloucester followed in 1686, Somerset in 1688, Cape May in 1692, and Burlington and Salem in 1694. Hunterdon (1714), Morris (1739), Cumberland (1748) and Sussex (1753) came later in the colonial period. The other eight counties date from the 1800s, each formed from older ones, for example Warren from Sussex in 1824, Camden from Gloucester in 1844 and Ocean from Monmouth in 1850. Union County, created from part of Essex in 1857, is the newest. As of 2026, 10 of the 21 counties are more than 300 years old.

Four New Jersey counties face the Atlantic Ocean. From north to south they are Monmouth, Ocean, Atlantic and Cape May, and the Jersey Shore runs through all four. Sandy Hook and Asbury Park are in Monmouth, Island Beach State Park and Long Beach Island in Ocean, Atlantic City in Atlantic County, and Wildwood and Cape May in Cape May County. These four counties hold about 71% of the water area in New Jersey's 21 counties, per the 2026 Census Gazetteer. Cape May alone has 368.8 square miles (955 km²) of water and 251.5 square miles (651 km²) of land. Cumberland, on Delaware Bay, ranks third for water at 194.5 square miles (504 km²), but it does not touch the ocean.

New Jersey has no legal definition of North, Central or South Jersey, so county lists vary by source. Transportation planning gives one formal three-way split. The North Jersey Transportation Planning Authority covers 13 counties: Bergen, Essex, Hudson, Hunterdon, Middlesex, Monmouth, Morris, Ocean, Passaic, Somerset, Sussex, Union and Warren. The Delaware Valley Regional Planning Commission, based in Philadelphia, covers Burlington, Camden, Gloucester and Mercer. The South Jersey Transportation Planning Organization covers Atlantic, Cape May, Cumberland and Salem. In everyday speech, Central Jersey usually refers to counties such as Middlesex, Monmouth, Somerset and Mercer, and you can draw your own grouping by coloring the counties on this map.

For a custom map of New Jersey, such as sales territories or county election results, use the free Ultimaps editor. You won't need an account. Pick any county, say Morris or Camden, and assign it a color by hand. Or import a spreadsheet listing the 21 county names with a value for each, such as 2024 population, and the counties are colored on a scale with a legend. Place pins on exact locations, for example an office in Newark or a venue in Atlantic City. Then adjust the palette, borders, labels and title. Exporting on the free plan gives you a standard PNG with a small Ultimaps credit, while high-resolution PNG, SVG and PDF exports are part of Pro.