| Caslav to Oignies | 549.30 mi (884.01 km) |
| Caslav to Oissel | 640.40 mi (1,030.63 km) |
| Caslav to Olivet | 628.24 mi (1,011.06 km) |
| Caslav to Ollioules | 650.91 mi (1,047.54 km) |
| Caslav to Olonne-sur-Mer | 821.85 mi (1,322.64 km) |
| Caslav to Oloron-Sainte-Marie | 888.05 mi (1,429.18 km) |
| Caslav to Onet Village | 711.86 mi (1,145.64 km) |
| Caslav to Onnaing | 522.78 mi (841.33 km) |
| Caslav to Orange | 637.47 mi (1,025.91 km) |
| Caslav to Orchies | 538.27 mi (866.27 km) |
| Caslav to Orleans | 627.05 mi (1,009.14 km) |
| Caslav to Orly | 590.26 mi (949.93 km) |
| Caslav to Ormesson-sur-Marne | 583.16 mi (938.50 km) |
| Caslav to Orsay | 600.09 mi (965.74 km) |
| Caslav to Orthez | 882.62 mi (1,420.44 km) |
