| Grays to Olivares | 1,021.57 mi (1,644.06 km) |
| Grays to Olivenza | 953.92 mi (1,535.19 km) |
| Grays to Olot | 650.05 mi (1,046.16 km) |
| Grays to Onate | 597.20 mi (961.11 km) |
| Grays to Onda | 795.95 mi (1,280.95 km) |
| Grays to Onteniente | 875.40 mi (1,408.81 km) |
| Grays to Orihuela | 927.20 mi (1,492.18 km) |
| Grays to Osuna | 1,019.20 mi (1,640.24 km) |
| Grays to Ourense | 739.41 mi (1,189.97 km) |
| Grays to Oviedo | 630.11 mi (1,014.07 km) |
| Grays to Paiporta | 833.16 mi (1,340.84 km) |
| Grays to Pajara | 1,763.97 mi (2,838.84 km) |
| Grays to Palafolls | 687.10 mi (1,105.78 km) |
| Grays to Palafrugell | 673.74 mi (1,084.28 km) |
| Grays to Palamos | 678.29 mi (1,091.60 km) |
