| Park Ridge to Orbetello | 4,737.84 mi (7,624.82 km) |
| Park Ridge to Oria | 5,078.81 mi (8,173.55 km) |
| Park Ridge to Oristano | 4,737.20 mi (7,623.78 km) |
| Park Ridge to Orta Nova | 4,965.47 mi (7,991.14 km) |
| Park Ridge to Orte | 4,783.92 mi (7,698.97 km) |
| Park Ridge to Ortona | 4,868.48 mi (7,835.06 km) |
| Park Ridge to Orvieto | 4,761.85 mi (7,663.45 km) |
| Park Ridge to Orzinuovi | 4,563.52 mi (7,344.28 km) |
| Park Ridge to Osimo | 4,783.04 mi (7,697.56 km) |
| Park Ridge to Ospitaletto | 4,562.63 mi (7,342.84 km) |
| Park Ridge to Ostuni | 5,066.14 mi (8,153.16 km) |
| Park Ridge to Ottaviano | 4,937.93 mi (7,946.83 km) |
| Park Ridge to Ovada | 4,543.77 mi (7,312.49 km) |
| Park Ridge to Ozieri | 4,725.85 mi (7,605.53 km) |
| Park Ridge to Paceco | 4,986.22 mi (8,024.55 km) |
