| Monticello to Orbetello | 4,823.18 mi (7,762.17 km) |
| Monticello to Oria | 5,151.83 mi (8,291.08 km) |
| Monticello to Oristano | 4,844.18 mi (7,795.96 km) |
| Monticello to Orta Nova | 5,041.22 mi (8,113.06 km) |
| Monticello to Orte | 4,865.29 mi (7,829.93 km) |
| Monticello to Ortona | 4,943.68 mi (7,956.08 km) |
| Monticello to Orvieto | 4,842.81 mi (7,793.75 km) |
| Monticello to Orzinuovi | 4,637.34 mi (7,463.07 km) |
| Monticello to Osimo | 4,855.57 mi (7,814.28 km) |
| Monticello to Ospitaletto | 4,635.17 mi (7,459.58 km) |
| Monticello to Ostuni | 5,138.23 mi (8,269.18 km) |
| Monticello to Ottaviano | 5,020.29 mi (8,079.38 km) |
| Monticello to Ovada | 4,625.69 mi (7,444.32 km) |
| Monticello to Ozieri | 4,828.00 mi (7,769.92 km) |
| Monticello to Paceco | 5,089.26 mi (8,190.37 km) |
