| Hennef to Olympia Heights (Florida) | 4,760.91 mi (7,661.94 km) |
| Hennef to Omaha (Nebraska) | 4,583.52 mi (7,376.47 km) |
| Hennef to On Top of the World Designated Place (Florida) | 4,670.97 mi (7,517.20 km) |
| Hennef to Onalaska (Wisconsin) | 4,282.19 mi (6,891.52 km) |
| Hennef to Oneida (New York) | 3,740.43 mi (6,019.65 km) |
| Hennef to Oneonta (New York) | 3,744.30 mi (6,025.87 km) |
| Hennef to Ontario (California) | 5,686.33 mi (9,151.26 km) |
| Hennef to Ontario (Oregon) | 5,084.49 mi (8,182.70 km) |
| Hennef to Opa-locka (Florida) | 4,748.45 mi (7,641.90 km) |
| Hennef to Opelika (Alabama) | 4,617.72 mi (7,431.50 km) |
| Hennef to Opelousas (Louisiana) | 4,991.88 mi (8,033.65 km) |
| Hennef to Orange (California) | 5,706.65 mi (9,183.97 km) |
| Hennef to Orange (Texas) | 5,078.20 mi (8,172.57 km) |
| Hennef to Orange City (Florida) | 4,638.26 mi (7,464.56 km) |
| Hennef to Orangeburg (South Carolina) | 4,394.68 mi (7,072.56 km) |
