| Caerfyrddin to Octeville | 193.31 mi (311.10 km) |
| Caerfyrddin to Oignies | 330.73 mi (532.26 km) |
| Caerfyrddin to Oissel | 293.84 mi (472.89 km) |
| Caerfyrddin to Olivet | 390.57 mi (628.57 km) |
| Caerfyrddin to Ollioules | 765.16 mi (1,231.41 km) |
| Caerfyrddin to Olonne-sur-Mer | 385.02 mi (619.64 km) |
| Caerfyrddin to Oloron-Sainte-Marie | 622.78 mi (1,002.26 km) |
| Caerfyrddin to Onet Village | 607.21 mi (977.20 km) |
| Caerfyrddin to Onnaing | 357.68 mi (575.64 km) |
| Caerfyrddin to Orange | 678.89 mi (1,092.57 km) |
| Caerfyrddin to Orchies | 341.00 mi (548.78 km) |
| Caerfyrddin to Orleans | 388.88 mi (625.85 km) |
| Caerfyrddin to Orly | 365.69 mi (588.52 km) |
| Caerfyrddin to Ormesson-sur-Marne | 369.12 mi (594.04 km) |
| Caerfyrddin to Orsay | 360.43 mi (580.05 km) |
