| Sint-Niklaas to Oignies | 69.26 mi (111.47 km) |
| Sint-Niklaas to Oissel | 184.24 mi (296.51 km) |
| Sint-Niklaas to Olivet | 249.18 mi (401.02 km) |
| Sint-Niklaas to Ollioules | 560.40 mi (901.88 km) |
| Sint-Niklaas to Olonne-sur-Mer | 417.42 mi (671.77 km) |
| Sint-Niklaas to Oloron-Sainte-Marie | 593.81 mi (955.64 km) |
| Sint-Niklaas to Onet Village | 475.29 mi (764.91 km) |
| Sint-Niklaas to Onnaing | 58.68 mi (94.43 km) |
| Sint-Niklaas to Orange | 486.63 mi (783.15 km) |
| Sint-Niklaas to Orchies | 61.58 mi (99.10 km) |
| Sint-Niklaas to Orleans | 246.57 mi (396.82 km) |
| Sint-Niklaas to Orly | 184.40 mi (296.77 km) |
| Sint-Niklaas to Ormesson-sur-Marne | 179.11 mi (288.25 km) |
| Sint-Niklaas to Orsay | 191.24 mi (307.78 km) |
| Sint-Niklaas to Orthez | 577.79 mi (929.87 km) |
