| Western Springs to Orbetello | 4,749.18 mi (7,643.06 km) |
| Western Springs to Oria | 5,090.42 mi (8,192.24 km) |
| Western Springs to Oristano | 4,747.94 mi (7,641.07 km) |
| Western Springs to Orta Nova | 4,977.02 mi (8,009.74 km) |
| Western Springs to Orte | 4,795.36 mi (7,717.38 km) |
| Western Springs to Ortona | 4,880.06 mi (7,853.70 km) |
| Western Springs to Orvieto | 4,773.30 mi (7,681.88 km) |
| Western Springs to Orzinuovi | 4,575.18 mi (7,363.04 km) |
| Western Springs to Osimo | 4,794.70 mi (7,716.32 km) |
| Western Springs to Ospitaletto | 4,574.32 mi (7,361.65 km) |
| Western Springs to Ostuni | 5,077.78 mi (8,171.89 km) |
| Western Springs to Ottaviano | 4,949.32 mi (7,965.16 km) |
| Western Springs to Ovada | 4,555.22 mi (7,330.92 km) |
| Western Springs to Ozieri | 4,736.74 mi (7,623.04 km) |
| Western Springs to Paceco | 4,997.04 mi (8,041.97 km) |
