| Castrop-Rauxel to Octeville | 414.57 mi (667.18 km) |
| Castrop-Rauxel to Oignies | 202.19 mi (325.39 km) |
| Castrop-Rauxel to Oissel | 313.38 mi (504.34 km) |
| Castrop-Rauxel to Olivet | 351.14 mi (565.11 km) |
| Castrop-Rauxel to Ollioules | 585.14 mi (941.70 km) |
| Castrop-Rauxel to Olonne-sur-Mer | 537.34 mi (864.77 km) |
| Castrop-Rauxel to Oloron-Sainte-Marie | 685.23 mi (1,102.77 km) |
| Castrop-Rauxel to Onet Village | 542.09 mi (872.40 km) |
| Castrop-Rauxel to Onnaing | 180.60 mi (290.65 km) |
| Castrop-Rauxel to Orange | 525.04 mi (844.98 km) |
| Castrop-Rauxel to Orchies | 191.96 mi (308.92 km) |
| Castrop-Rauxel to Orleans | 348.89 mi (561.48 km) |
| Castrop-Rauxel to Orly | 291.64 mi (469.35 km) |
| Castrop-Rauxel to Ormesson-sur-Marne | 284.85 mi (458.42 km) |
| Castrop-Rauxel to Orsay | 300.63 mi (483.81 km) |
