| Caerfyrddin to Opwijk | 371.17 mi (597.35 km) |
| Caerfyrddin to Ostend | 313.83 mi (505.05 km) |
| Caerfyrddin to Oud-Heverlee | 393.80 mi (633.75 km) |
| Caerfyrddin to Oud-Turnhout | 400.68 mi (644.83 km) |
| Caerfyrddin to Oudenaarde | 348.39 mi (560.68 km) |
| Caerfyrddin to Oudenburg | 317.81 mi (511.47 km) |
| Caerfyrddin to Oupeye | 437.28 mi (703.73 km) |
| Caerfyrddin to Overijse | 388.99 mi (626.02 km) |
| Caerfyrddin to Overpelt | 420.29 mi (676.39 km) |
| Caerfyrddin to Paal | 412.17 mi (663.33 km) |
| Caerfyrddin to Peer | 422.89 mi (680.58 km) |
| Caerfyrddin to Pepinster | 447.14 mi (719.61 km) |
| Caerfyrddin to Peruwelz | 354.19 mi (570.01 km) |
| Caerfyrddin to Perwez | 403.75 mi (649.77 km) |
| Caerfyrddin to Philippeville | 401.61 mi (646.33 km) |
