Founded in 1753, Sussex County is one of 21 counties in the state of New Jersey. Historically, Sussex County was formed from Morris County. The city of Newton is the county seat. With FIPS code of 37, Sussex County has a population of 145,543 and area of 521 square miles (1,349 km2).
List of all cities in Sussex County, NJ alphabetically
| City/Town | Postal Code | Area Code |
| Andover, NJ | 07821 | 973/862 |
| Augusta, NJ | 07822 | 973/862 |
| Barry Lakes, NJ | 07422 | 973/862 |
| Beaver Lake, NJ | 07416 | 973/862 |
| Beemerville, NJ | 07461 | 973/862 |
| Branchville, NJ | 07826 | 973/862 |
| 07827 | 973/862 | |
| 07890 | 973/862 | |
| Byram Township, NJ | 07821 | 973/862 |
| Cliffwood Lake, NJ | 07460 | 973/862 |
| Colesville, NJ | 07461 | 973/862 |
| Franklin, NJ | 07416 | 973/862 |
| Fredon, NJ | 07860 | 973/862 |
| Fredon Township, NJ | 07860 | 973/862 |
| Gerard, NJ | 07460 | 973/862 |
| Glasser, NJ | 07837 | 973/862 |
| Glenwood, NJ | 07418 | 973/862 |
| Green Township, NJ | 07821 | 973/862 |
| Greendell, NJ | 07839 | 973/862 |
| Hamburg, NJ | 07419 | 973/862 |
| Hardyston, NJ | 07419 | 973/862 |
| 07460 | 973/862 | |
| High Point, NJ | 07461 | 973/862 |
| High Point Park, NJ | 07461 | 973/862 |
| Highland Lakes, NJ | 07422 | 973/862 |
| Highland Lks, NJ | 07422 | 973/862 |
| Hopatcong, NJ | 07843 | 973/862 |
| Lafayette, NJ | 07848 | 973/862 |
| Lake Stockholm, NJ | 07460 | 973/862 |
| Lake Tamarack, NJ | 07460 | 973/862 |
| Layton, NJ | 07851 | 973/862 |
| McAfee, NJ | 07428 | 973/862 |
| Middleville, NJ | 07855 | 973/862 |
| Montague, NJ | 07827 | 973/862 |
| Newton, NJ | 07860 | 973/862 |
| Ogdensburg, NJ | 07439 | 973/862 |
| Sandyston, NJ | 07826 | 973/862 |
| 07827 | 973/862 | |
| 07851 | 973/862 | |
| Selected Risks Insurance Co, NJ | 07890 | 973/862 |
| Silver Lake, NJ | 07460 | 973/862 |
| Sparta, NJ | 07871 | 973/862 |
| Stanhope, NJ | 07874 | 973/862 |
| Stillwater, NJ | 07875 | 973/862 |
| Stockholm, NJ | 07460 | 973/862 |
| Sussex, NJ | 07461 | 973/862 |
| Swartswood, NJ | 07877 | 973/862 |
| Tranquility, NJ | 07879 | 908 |
| Vernon, NJ | 07462 | 973/862 |
| Wallkill Lake, NJ | 07461 | 973/862 |
| Wallpack Center, NJ | 07881 | 973/862 |
| Wantage, NJ | 07461 | 973/862 |