Town
- Newton (county seat)
Boroughs
- Andover Borough
- Branchville
- Franklin
- Hamburg
- Hopatcong
- Ogdensburg
- Stanhope
- Sussex
- Victory Gardens *(Note: This is actually in Morris County, often confused—not in Sussex)
Townships
- Andover Township
- Byram Township
- Frankford Township
- Fredon Township
- Green Township
- Hampton Township
- Hardyston Township
- Lafayette Township
- Montague Township
- Sandyston Township
- Sparta Township
- Stillwater Township
- Vernon Township
- Walpack Township
- Wantage Township