| Gennep to Olympia Heights (Florida) | 4,689.83 mi (7,547.55 km) |
| Gennep to Omaha (Nebraska) | 4,500.09 mi (7,242.19 km) |
| Gennep to On Top of the World Designated Place (Florida) | 4,596.90 mi (7,398.00 km) |
| Gennep to Onalaska (Wisconsin) | 4,199.03 mi (6,757.68 km) |
| Gennep to Oneida (New York) | 3,661.56 mi (5,892.71 km) |
| Gennep to Oneonta (New York) | 3,665.96 mi (5,899.79 km) |
| Gennep to Ontario (California) | 5,601.20 mi (9,014.26 km) |
| Gennep to Ontario (Oregon) | 4,999.45 mi (8,045.84 km) |
| Gennep to Opa-locka (Florida) | 4,677.32 mi (7,527.42 km) |
| Gennep to Opelika (Alabama) | 4,540.42 mi (7,307.10 km) |
| Gennep to Opelousas (Louisiana) | 4,912.80 mi (7,906.39 km) |
| Gennep to Orange (California) | 5,621.52 mi (9,046.97 km) |
| Gennep to Orange (Texas) | 4,998.64 mi (8,044.53 km) |
| Gennep to Orange City (Florida) | 4,564.80 mi (7,346.34 km) |
| Gennep to Orangeburg (South Carolina) | 4,318.94 mi (6,950.66 km) |
