| Cincinnati to Orbetello | 4,722.55 mi (7,600.20 km) |
| Cincinnati to Oria | 5,070.44 mi (8,160.08 km) |
| Cincinnati to Oristano | 4,706.03 mi (7,573.63 km) |
| Cincinnati to Orta Nova | 4,955.78 mi (7,975.56 km) |
| Cincinnati to Orte | 4,771.24 mi (7,678.57 km) |
| Cincinnati to Ortona | 4,859.77 mi (7,821.05 km) |
| Cincinnati to Orvieto | 4,749.60 mi (7,643.74 km) |
| Cincinnati to Orzinuovi | 4,557.70 mi (7,334.91 km) |
| Cincinnati to Osimo | 4,776.78 mi (7,687.48 km) |
| Cincinnati to Ospitaletto | 4,557.73 mi (7,334.96 km) |
| Cincinnati to Ostuni | 5,058.51 mi (8,140.89 km) |
| Cincinnati to Ottaviano | 4,923.61 mi (7,923.78 km) |
| Cincinnati to Ovada | 4,532.18 mi (7,293.84 km) |
| Cincinnati to Ozieri | 4,698.33 mi (7,561.22 km) |
| Cincinnati to Paceco | 4,956.51 mi (7,976.73 km) |
