Founded in 1746, Johnston County is one of 100 counties in the state of North Carolina. Historically, Johnston County was formed from Craven County. The city of Smithfield is the county seat. With FIPS code of 101, Johnston County has a population of 226,504 and area of 796 square miles (2,062 km2).
List of all cities in Johnston County, NC alphabetically
| City/Town | Postal Code | Area Code |
| Archers Lodge, NC | 27520 | 919/984 |
| Bagley, NC | 27542 | 919/984 |
| Benson, NC | 27504 | 919/984 |
| Clayton, NC | 27520 | 919/984 |
| 27527 | 919/984 | |
| 27528 | 919/984 | |
| Four Oaks, NC | 27524 | 919/984 |
| Kenly, NC | 27542 | 919/984 |
| Micro, NC | 27555 | 919/984 |
| Pine Level, NC | 27568 | 919/984 |
| Princeton, NC | 27569 | 919/984 |
| Selma, NC | 27576 | 919/984 |
| Smithfield, NC | 27577 | 919/984 |
| Whitley Heights, NC | 27520 | 919/984 |
| Wilsons Mills, NC | 27593 | 919/984 |