| Fort Madison to Orbetello | 4,939.41 mi (7,949.21 km) |
| Fort Madison to Oria | 5,279.05 mi (8,495.81 km) |
| Fort Madison to Oristano | 4,940.89 mi (7,951.59 km) |
| Fort Madison to Orta Nova | 5,166.00 mi (8,313.87 km) |
| Fort Madison to Orte | 4,985.05 mi (8,022.66 km) |
| Fort Madison to Ortona | 5,068.89 mi (8,157.59 km) |
| Fort Madison to Orvieto | 4,962.91 mi (7,987.04 km) |
| Fort Madison to Orzinuovi | 4,763.59 mi (7,666.25 km) |
| Fort Madison to Osimo | 4,983.06 mi (8,019.45 km) |
| Fort Madison to Ospitaletto | 4,762.52 mi (7,664.54 km) |
| Fort Madison to Ostuni | 5,266.25 mi (8,475.21 km) |
| Fort Madison to Ottaviano | 5,139.25 mi (8,270.82 km) |
| Fort Madison to Ovada | 4,744.84 mi (7,636.07 km) |
| Fort Madison to Ozieri | 4,929.13 mi (7,932.66 km) |
| Fort Madison to Paceco | 5,189.67 mi (8,351.97 km) |
