| Old Tree Swamp | rises in W Hertford County and flows SE into Potecasi Creek. |
| Old Weeksville | See Weeksville. |
| Old Woman's Swamp | See Gilletts Creek. |
| Oldfield Creek | See Redbank Creek. |
| Oldfield Gap | N Graham County between Yellow Creek Mountains and Fork Ridge. |
| Oldfield Gap | on the Madison-Yancey county line near Indian Creek. |
| Oldfield Swamp | rises in S Robeson County and flows SE into Hog Swamp. |
| Oldfields Township | SW Ashe County. Named for muster ground and drill field used by Benjamin Cleveland during the Revolution. |
| Oldham | community in N Forsyth County served by post office, 1883-1901. |
| Olds | community in S Currituck County. Known locally as Olds Hill for a sand hill nearby. |