| Castelo Branco to Olivenza | 81.00 mi (130.36 km) |
| Castelo Branco to Olot | 545.54 mi (877.96 km) |
| Castelo Branco to Onate | 344.48 mi (554.39 km) |
| Castelo Branco to Onda | 383.64 mi (617.41 km) |
| Castelo Branco to Onteniente | 374.69 mi (603.00 km) |
| Castelo Branco to Orihuela | 371.77 mi (598.30 km) |
| Castelo Branco to Osuna | 220.64 mi (355.08 km) |
| Castelo Branco to Ourense | 175.12 mi (281.83 km) |
| Castelo Branco to Oviedo | 259.31 mi (417.32 km) |
| Castelo Branco to Paiporta | 377.75 mi (607.92 km) |
| Castelo Branco to Pajara | 877.02 mi (1,411.42 km) |
| Castelo Branco to Palafolls | 551.28 mi (887.21 km) |
| Castelo Branco to Palafrugell | 575.32 mi (925.88 km) |
| Castelo Branco to Palamos | 572.66 mi (921.60 km) |
| Castelo Branco to Palencia | 216.99 mi (349.22 km) |
