| Mostoles to Orbetello | 794.00 mi (1,277.81 km) |
| Mostoles to Oria | 1,128.24 mi (1,815.72 km) |
| Mostoles to Oristano | 658.36 mi (1,059.53 km) |
| Mostoles to Orta Nova | 1,023.64 mi (1,647.40 km) |
| Mostoles to Orte | 853.73 mi (1,373.94 km) |
| Mostoles to Ortona | 955.86 mi (1,538.30 km) |
| Mostoles to Orvieto | 841.36 mi (1,354.04 km) |
| Mostoles to Orzinuovi | 780.20 mi (1,255.60 km) |
| Mostoles to Osimo | 916.45 mi (1,474.88 km) |
| Mostoles to Ospitaletto | 790.50 mi (1,272.19 km) |
| Mostoles to Ostuni | 1,123.93 mi (1,808.80 km) |
| Mostoles to Ottaviano | 961.37 mi (1,547.18 km) |
| Mostoles to Ovada | 702.56 mi (1,130.67 km) |
| Mostoles to Ozieri | 676.21 mi (1,088.25 km) |
| Mostoles to Paceco | 893.02 mi (1,437.18 km) |
