| Castelfidardo to Octeville | 835.77 mi (1,345.05 km) |
| Castelfidardo to Oignies | 692.87 mi (1,115.07 km) |
| Castelfidardo to Oissel | 717.64 mi (1,154.92 km) |
| Castelfidardo to Olivet | 638.29 mi (1,027.23 km) |
| Castelfidardo to Ollioules | 387.65 mi (623.86 km) |
| Castelfidardo to Olonne-sur-Mer | 776.52 mi (1,249.68 km) |
| Castelfidardo to Oloron-Sainte-Marie | 710.71 mi (1,143.78 km) |
| Castelfidardo to Onet Village | 548.26 mi (882.35 km) |
| Castelfidardo to Onnaing | 669.11 mi (1,076.83 km) |
| Castelfidardo to Orange | 437.94 mi (704.79 km) |
| Castelfidardo to Orchies | 684.76 mi (1,102.02 km) |
| Castelfidardo to Orleans | 639.03 mi (1,028.42 km) |
| Castelfidardo to Orly | 645.94 mi (1,039.53 km) |
| Castelfidardo to Ormesson-sur-Marne | 641.70 mi (1,032.71 km) |
| Castelfidardo to Orsay | 652.48 mi (1,050.07 km) |
