| Santander to Orbetello | 761.70 mi (1,225.84 km) |
| Santander to Oria | 1,116.71 mi (1,797.17 km) |
| Santander to Oristano | 684.42 mi (1,101.46 km) |
| Santander to Orta Nova | 1,004.28 mi (1,616.24 km) |
| Santander to Orte | 820.30 mi (1,320.14 km) |
| Santander to Ortona | 922.68 mi (1,484.91 km) |
| Santander to Orvieto | 803.46 mi (1,293.04 km) |
| Santander to Orzinuovi | 690.01 mi (1,110.47 km) |
| Santander to Osimo | 865.29 mi (1,392.55 km) |
| Santander to Ospitaletto | 697.99 mi (1,123.31 km) |
| Santander to Ostuni | 1,109.42 mi (1,785.45 km) |
| Santander to Ottaviano | 951.63 mi (1,531.50 km) |
| Santander to Ovada | 623.02 mi (1,002.65 km) |
| Santander to Ozieri | 686.01 mi (1,104.03 km) |
| Santander to Paceco | 934.26 mi (1,503.55 km) |
