Middlesex County, New Jersey

Middlesex County profile, demographic data, and geographic information.

Local Government & Public Administration

Authoritative general-purpose local government units serving this area U.S. Census Bureau GUS (2026) / GMAF

Government Unit	Unit Type	Jurisdiction Role	Contact / Address
COUNTY OF MIDDLESEX GUS Population: 890,119 (2024) ID: 170104	County	Official County Government	Contact: DIRECTOR 75 BAYARD ST, NEW BRUNSWICK NJ 08901-2112
TOWNSHIP OF EDISON GUS Population: 110,002 (2024) ID: 170312	Township	Municipal Government Within County	Contact: TOWN CLERK 100 MUNICIPAL BLVD, EDISON NJ 08817-3367
TOWNSHIP OF WOODBRIDGE GUS Population: 106,101 (2024) ID: 130897	Township	Municipal Government Within County	Contact: MAYOR 1 MAIN ST, STE 1, WOODBRIDGE NJ 07095-3352
TOWNSHIP OF OLD BRIDGE GUS Population: 70,506 (2024) ID: 170309	Township	Municipal Government Within County	Contact: BUSINESS ADMIN 1 OLD BRIDGE PLZ, OLD BRIDGE NJ 08857-2474
TOWNSHIP OF PISCATAWAY GUS Population: 62,733 (2024) ID: 130896	Township	Municipal Government Within County	Contact: TWP ADMINISTRATOR 455 HOES LN, PISCATAWAY NJ 08854-4147
CITY OF NEW BRUNSWICK GUS Population: 57,487 (2024) ID: 193736	Municipal	Municipal Government Within County	Contact: MANAGEMENT SPECIALIST 78 BAYARD STREET, NEW BRUNSWICK NJ 08901
CITY OF PERTH AMBOY GUS Population: 56,939 (2024) ID: 170194	Municipal	Municipal Government Within County	Contact: MAYOR 260 HIGH ST, PERTH AMBOY NJ 08861-4491
TOWNSHIP OF EAST BRUNSWICK GUS Population: 51,086 (2024) ID: 109153	Township	Municipal Government Within County	Contact: CFO 1 JEAN WALLING CIVIC CENTER DR, EAST BRUNSWICK NJ 08816
TOWNSHIP OF MONROE GUS Population: 50,157 (2024) ID: 170310	Township	Municipal Government Within County	Contact: ASST TO THE ADMINISTRATOR 1 MUNICIPAL PLZ, MONROE TWP NJ 08831-1900
TOWNSHIP OF SOUTH BRUNSWICK GUS Population: 47,896 (2024) ID: 184037	Township	Municipal Government Within County	Contact: DIRECTOR OF PLANNING PO BOX 190, MONMOUTH JUNCTION NJ 08852-0190
BOROUGH OF SAYREVILLE GUS Population: 47,165 (2024) ID: 186549	Municipal	Municipal Government Within County	Contact: MUNICIPAL CLERK 167 MAIN ST, SAYREVILLE NJ 08872-1149
TOWNSHIP OF NORTH BRUNSWICK GUS Population: 45,323 (2024) ID: 170311	Township	Municipal Government Within County	Contact: MAYOR 710 HERMANN RD, NORTH BRUNSWICK NJ 08902-2850
BOROUGH OF CARTERET GUS Population: 26,003 (2024) ID: 130843	Municipal	Municipal Government Within County	Contact: MAYOR 100 COOKE AVENUE, CARTERET NJ 07008-3096
BOROUGH OF SOUTH PLAINFIELD GUS Population: 25,062 (2024) ID: 170195	Municipal	Municipal Government Within County	Contact: AMY ANTONIDES 2480 PLAINFIELD AVE, SOUTH PLAINFIELD NJ 07080-3596
TOWNSHIP OF PLAINSBORO GUS Population: 24,558 (2024) ID: 109155	Township	Municipal Government Within County	Contact: TOWNSHIP ADMINISTRATOR 641 PLAINSBORO RD, PLAINSBORO NJ 08536-2094
BOROUGH OF SOUTH RIVER GUS Population: 16,392 (2024) ID: 170196	Municipal	Municipal Government Within County	Contact: CHIEF FINANCIAL OFFICER 48 WASHINGTON ST, SOUTH RIVER NJ 08882-1247
BOROUGH OF METUCHEN GUS Population: 15,470 (2024) ID: 170192	Municipal	Municipal Government Within County	Contact: CLERK 500 MAIN ST, METUCHEN NJ 08840-1402
BOROUGH OF HIGHLAND PARK GUS Population: 15,386 (2024) ID: 225460	Municipal	Municipal Government Within County	Contact: ADMINISTRATOR/CFO 221 S 5TH AVE, HIGHLAND PARK NJ 08904-2600
BOROUGH OF MIDDLESEX GUS Population: 14,874 (2024) ID: 170193	Municipal	Municipal Government Within County	Contact: MUNICIPAL CLERK 1200 MOUNTAIN AVE, MIDDLESEX NJ 08846-2700
CITY OF SOUTH AMBOY GUS Population: 10,549 (2024) ID: 130846	Municipal	Municipal Government Within County	Contact: MAYOR 140 N BROADWAY, SOUTH AMBOY NJ 08879-1642
BOROUGH OF DUNELLEN GUS Population: 8,411 (2024) ID: 170190	Municipal	Municipal Government Within County	Contact: ADMINISTRATOR 355 NORTH AVE, DUNELLEN NJ 08812-1295
BOROUGH OF SPOTSWOOD GUS Population: 8,306 (2024) ID: 170197	Municipal	Municipal Government Within County	Contact: BUSINIESS ADMINISTRATOR 77 SUMMERHILL RD, SPOTSWOOD NJ 08884-1233
BOROUGH OF MILLTOWN GUS Population: 7,170 (2024) ID: 130845	Municipal	Municipal Government Within County	Contact: MAYOR 39 WASHINGTON AVE, MILLTOWN NJ 08850-1219
BOROUGH OF JAMESBURG GUS Population: 5,869 (2024) ID: 130844	Municipal	Municipal Government Within County	Contact: ADMINISTRATOR 131 PERRINEVILLE RD, JAMESBURG NJ 08831-1672
TOWNSHIP OF CRANBURY GUS Population: 4,170 (2024) ID: 130895	Township	Municipal Government Within County	Contact: FINANCE DEPARTMENT 23A N MAIN ST, CRANBURY NJ 08512-3257
BOROUGH OF HELMETTA GUS Population: 2,504 (2024) ID: 170191	Municipal	Municipal Government Within County	Contact: MUNICIPAL CLERK 51 MAIN ST, HELMETTA NJ 08828-1127