| Oberlin | formerly a community in central Wake County NW of Raleigh but now a part of the city of Raleigh. |
| Obids | community in S Ashe County. Alt. approx. 2,800. |
| Obids Creek | rises in SE Ashe county and flows N into South Fork New River. |
| Obids Township | SE Ashe County. |
| Obies Creek | rises in N Chatham County and flows NE into Orange County, where it enters Morgan Creek. |
| Observer | community in SW Mecklenburg County served by post office, 1900-1915. Named for local Observer School, which in turn was named for the Charlotte Observer |
| Ocala | community in S Jackson County on Fowler Creek. |
| Occacock | See Ocracoke. |
| Occam | See Croatan Sound. |
| Occaneechi Mountain | central Orange County S of the town of Hillsborough. Named for an Indian tribe mentioned frequently in seventeenth- and eighteenth-century records. The mountain is referred to in a letter of January 31, 1767, by Governor Tryon. Appears but is not named on the Collet map, 1770. Called Occaneeche Hills on the Kerr map, 1882. Alt. approx. 700. Now a local park. |