| San Marino to Orbetello | 6,252.55 mi (10,062.50 km) |
| San Marino to Oria | 6,561.52 mi (10,559.74 km) |
| San Marino to Oristano | 6,296.33 mi (10,132.96 km) |
| San Marino to Orta Nova | 6,456.02 mi (10,389.96 km) |
| San Marino to Orte | 6,289.43 mi (10,121.85 km) |
| San Marino to Ortona | 6,359.12 mi (10,234.02 km) |
| San Marino to Orvieto | 6,266.74 mi (10,085.35 km) |
| San Marino to Orzinuovi | 6,055.32 mi (9,745.10 km) |
| San Marino to Osimo | 6,268.85 mi (10,088.74 km) |
| San Marino to Ospitaletto | 6,051.61 mi (9,739.12 km) |
| San Marino to Ostuni | 6,546.87 mi (10,536.17 km) |
| San Marino to Ottaviano | 6,443.65 mi (10,370.05 km) |
| San Marino to Ovada | 6,053.53 mi (9,742.21 km) |
| San Marino to Ozieri | 6,275.53 mi (10,099.49 km) |
| San Marino to Paceco | 6,535.20 mi (10,517.38 km) |
