| Castellanza to Octeville | 563.05 mi (906.14 km) |
| Castellanza to Oignies | 431.98 mi (695.20 km) |
| Castellanza to Oissel | 445.96 mi (717.71 km) |
| Castellanza to Olivet | 365.81 mi (588.71 km) |
| Castellanza to Ollioules | 228.07 mi (367.04 km) |
| Castellanza to Olonne-sur-Mer | 515.07 mi (828.93 km) |
| Castellanza to Oloron-Sainte-Marie | 497.84 mi (801.19 km) |
| Castellanza to Onet Village | 319.95 mi (514.91 km) |
| Castellanza to Onnaing | 410.56 mi (660.74 km) |
| Castellanza to Orange | 224.77 mi (361.74 km) |
| Castellanza to Orchies | 425.08 mi (684.10 km) |
| Castellanza to Orleans | 366.48 mi (589.79 km) |
| Castellanza to Orly | 374.05 mi (601.98 km) |
| Castellanza to Ormesson-sur-Marne | 370.11 mi (595.63 km) |
| Castellanza to Orsay | 380.29 mi (612.01 km) |
