| San Mateo to Orbetello | 6,185.29 mi (9,954.27 km) |
| San Mateo to Oria | 6,478.32 mi (10,425.85 km) |
| San Mateo to Oristano | 6,246.95 mi (10,053.50 km) |
| San Mateo to Orta Nova | 6,377.05 mi (10,262.87 km) |
| San Mateo to Orte | 6,218.16 mi (10,007.17 km) |
| San Mateo to Ortona | 6,281.39 mi (10,108.93 km) |
| San Mateo to Orvieto | 6,195.53 mi (9,970.74 km) |
| San Mateo to Orzinuovi | 5,981.85 mi (9,626.85 km) |
| San Mateo to Osimo | 6,190.48 mi (9,962.61 km) |
| San Mateo to Ospitaletto | 5,977.15 mi (9,619.29 km) |
| San Mateo to Ostuni | 6,463.13 mi (10,401.40 km) |
| San Mateo to Ottaviano | 6,370.57 mi (10,252.44 km) |
| San Mateo to Ovada | 5,986.81 mi (9,634.85 km) |
| San Mateo to Ozieri | 6,222.29 mi (10,013.81 km) |
| San Mateo to Paceco | 6,478.65 mi (10,426.38 km) |
