| Enniskillen to Olympia Heights (Florida) | 4,105.09 mi (6,606.50 km) |
| Enniskillen to Omaha (Nebraska) | 3,922.40 mi (6,312.50 km) |
| Enniskillen to On Top of the World Designated Place (Florida) | 4,006.68 mi (6,448.12 km) |
| Enniskillen to Onalaska (Wisconsin) | 3,619.45 mi (5,824.95 km) |
| Enniskillen to Oneida (New York) | 3,068.80 mi (4,938.76 km) |
| Enniskillen to Oneonta (New York) | 3,072.92 mi (4,945.39 km) |
| Enniskillen to Ontario (California) | 5,054.12 mi (8,133.82 km) |
| Enniskillen to Ontario (Oregon) | 4,476.64 mi (7,204.46 km) |
| Enniskillen to Opa-locka (Florida) | 4,092.47 mi (6,586.19 km) |
| Enniskillen to Opelika (Alabama) | 3,947.34 mi (6,352.63 km) |
| Enniskillen to Opelousas (Louisiana) | 4,320.21 mi (6,952.70 km) |
| Enniskillen to Orange (California) | 5,074.53 mi (8,166.67 km) |
| Enniskillen to Orange (Texas) | 4,406.52 mi (7,091.61 km) |
| Enniskillen to Orange City (Florida) | 3,975.53 mi (6,398.00 km) |
| Enniskillen to Orangeburg (South Carolina) | 3,726.76 mi (5,997.64 km) |
