Founded in 1734, Onslow County is one of 100 counties in the state of North Carolina. Historically, Onslow County was formed from New Hanover County. The city of Jacksonville is the county seat. With FIPS code of 133, Onslow County has a population of 206,160 and area of 909 square miles (2,354 km2).
List of all cities in Onslow County, NC alphabetically
| City/Town | Postal Code | Area Code |
| Camp Lejeune, NC | 28542 | 910 |
| 28547 | 910 | |
| Camp Lejeune Mcb, NC | 28542 | 910 |
| Cape Carteret, NC | 28584 | 252 |
| Cedar Point, NC | 28584 | 252 |
| CL Naval Hospital, NC | 28547 | 910 |
| Holly Ridge, NC | 28445 | 910 |
| Hubert, NC | 28539 | 910 |
| Jacksonville, NC | 28540 | 910 |
| 28541 | 910 | |
| 28542 | 910 | |
| 28543 | 910 | |
| 28544 | 910 | |
| 28545 | 910 | |
| 28546 | 910 | |
| Lejeune, NC | 28542 | 910 |
| McCutcheon Field, NC | 28545 | 910 |
| Midway Park, NC | 28544 | 910 |
| Naval Hospital, NC | 28547 | 910 |
| New River Marine Corps Air S, NC | 28540 | 910 |
| North Topsail Beach, NC | 28460 | 910 |
| Peletier, NC | 28584 | 252 |
| Richlands, NC | 28574 | 910 |
| Sneads Ferry, NC | 28460 | 910 |
| Surf City Fin, NC | 28445 | 910 |
| Swansboro, NC | 28584 | 252 |
| Tarawa, NC | 28543 | 910 |
| Tarawa Terrace, NC | 28543 | 910 |
| Topsail Beach, NC | 28445 | 910 |