Atlantic County	001	Mays Landing	1837	Gloucester County	The Atlantic Ocean, which forms the county's eastern border	489.39	274,549	561 sq mi
(1,453 km2)	A county in the southeast part of the state. It is medium in size.
Bergen County	003	Hackensack	1683	One of 4 original counties created in East Jersey	Bergen, New Netherland settlement	3868.02	905,116	234 sq mi
(606 km2)	A county in the northeast part of the state. It is small.
Burlington County	005	Mount Holly	1694	One of two original counties created in West Jersey	The old ancient name for an inland market near Bridlington, England	557.43	448,734	805 sq mi
(2,085 km2)	A county in the southern part of the state. It gets wider as it goes northeast. It is one of the largest counties.
Camden County	007	Camden	1844	Gloucester County	Charles Pratt, 1st Earl Camden (1714.1794), an English supporter of the colonists during the American Revolution[13]	2,313.77	513,657	222 sq mi
(575 km2)	A county in the southwest part of the state. It is very small.
Cape May County	009	Cape May Court House	1692	Burlington County	The 17th-century Dutch explorer Cornelius Jacobsen Mey, who explored and surveyed the Delaware Bay to the south of the county	381.43	97,265	255 sq mi
(660 km2)	A county the makes up the southern tip of the state. It is one of the smallest.
Cumberland County	011	Bridgeton	1748	Salem County	Prince William, Duke of Cumberland (1721.1765), second son of George II of England and military victor at the Battle of Culloden in 1746	320.85	156,898	489 sq mi
(1,267 km2)	A county in the southern part of the state, west of the tip. It is averagely sized.
Essex County	013	Newark	1683	One of four original counties created in East Jersey	The county of Essex in England	6,221.98	783,969	126 sq mi
(326 km2)	A county in the northeast part of the state. It is one of the smallest.
Gloucester County	015	Woodbury	1686	Burlington County	The city of Gloucester, England	887.04	288,288	325 sq mi
(842 km2)	A county in the southwest part of the state. It is averagely sized.
Hudson County	017	Jersey City	1840	Bergen County	The English explorer Henry Hudson (d. 1611), who explored portions of New Jersey's coastline	13,495.02	634,266	47 sq mi
(122 km2)	A county in the northeast part of the state. It is the smallest county.
Hunterdon County	019	Flemington	1714	Burlington County	Robert Hunter (1664.1734), the Colonial Governor of New Jersey from 1710 to 1720	298.49	128,349	430 sq mi
(1,114 km2)	A county in the west part of the state, just north of the divide between north and south. It is averagely sized.
Mercer County	021	Trenton	1838	Burlington County, Hunterdon County, Middlesex County, and Somerset County	The Continental Army General Hugh Mercer (1726.1777), who died at the Battle of Princeton[14]	1,621.74	366,513	226 sq mi
(585 km2)	A county in the western part of the state, just above an indentation. It is small compared to its neighbors.
Middlesex County	023	New Brunswick	1683	One of four original counties created in East Jersey	The historic county of Middlesex in England	2,604.05	809,858	311 sq mi
(805 km2)	A county in the northern part of the state. It is averagely sized.
Monmouth County	025	Freehold Borough	1683	One of four original counties created in East Jersey	The historic county of Monmouthshire in Wales	1,335.55	630,380	472 sq mi
(1,222 km2)	A county in the central-western part of the state. It is averagely sized and gets skinnier in the west.
Morris County	027	Morristown	1739	Hunterdon County	Colonel Lewis Morris (1671.1746), colonial governor of New Jersey at the time of the county's formation[15][16]	1,049.63	492,276	469 sq mi
(1,215 km2)	A county in the northern part of the state, landlocked by other counties. It is well-sized.
Ocean County	029	Toms River	1850	Monmouth County	The Atlantic Ocean, which forms the eastern border of New Jersey	629.44	576,567	636 sq mi
(1,647 km2)	A county in the southeast part of the state. It is large and gets skinnier in the south.
Passaic County	031	Paterson	1837	Bergen County and Essex County	"Pasaeck", a Lenape word meaning "valley"	2,709.33	501,226	185 sq mi
(479 km2)	A county in the north-central part of the state. It is small, and has two wide parts with a skinny area between them.
Salem County	033	Salem	1694	One of two original counties created in West Jersey	A Hebrew word meaning "peace"	195.51	66,083	338 sq mi
(875 km2)	A county in the southwest part of the state. It is averagely sized.
Somerset County	035	Somerville	1688	Middlesex County	The county of Somerset in England	1,060.47	323,444	305 sq mi
(790 km2)	A county landlocked by other counties in the northern part of the state. It is small.
Sussex County	037	Newton	1753	Morris County	The county of Sussex in England	286.5	149,265	521 sq mi
(1,349 km2)	A county in the northwest corner of the state. It is larger than most surrounding counties.
Union County	039	Elizabeth	1857	Essex County	The union of the United States, which was being threatened by the dispute over slavery	5,208.73	536,499	103 sq mi
(267 km2)	A county in the northeast part of the state, on an indentation. It is one of the smallest counties.
Warren County	041	Belvidere	1824	Sussex County	The American Revolutionary War General Joseph Warren (1741.1775), killed at the Battle of Bunker Hill	303.61	108,692	358 sq mi
(927 km2)	A county in the northwest part of the state. It is averagely sized.