| Castel San Giorgio to Octeville | 999.54 mi (1,608.61 km) |
| Castel San Giorgio to Oignies | 874.13 mi (1,406.77 km) |
| Castel San Giorgio to Oissel | 886.81 mi (1,427.18 km) |
| Castel San Giorgio to Olivet | 798.01 mi (1,284.28 km) |
| Castel San Giorgio to Ollioules | 482.81 mi (777.01 km) |
| Castel San Giorgio to Olonne-sur-Mer | 911.94 mi (1,467.62 km) |
| Castel San Giorgio to Oloron-Sainte-Marie | 802.32 mi (1,291.20 km) |
| Castel San Giorgio to Onet Village | 663.03 mi (1,067.04 km) |
| Castel San Giorgio to Onnaing | 851.65 mi (1,370.60 km) |
| Castel San Giorgio to Orange | 554.39 mi (892.20 km) |
| Castel San Giorgio to Orchies | 866.72 mi (1,394.85 km) |
| Castel San Giorgio to Orleans | 799.15 mi (1,286.11 km) |
| Castel San Giorgio to Orly | 814.89 mi (1,311.43 km) |
| Castel San Giorgio to Ormesson-sur-Marne | 811.46 mi (1,305.92 km) |
| Castel San Giorgio to Orsay | 820.39 mi (1,320.28 km) |
