| Fort Madison to Oberkirch | 4,565.65 mi (7,347.70 km) |
| Fort Madison to Obernburg am Main | 4,552.87 mi (7,327.13 km) |
| Fort Madison to Obernkirchen | 4,456.62 mi (7,172.23 km) |
| Fort Madison to Oberschleissheim | 4,706.35 mi (7,574.14 km) |
| Fort Madison to Oberstdorf | 4,693.44 mi (7,553.36 km) |
| Fort Madison to Obertraubling | 4,698.30 mi (7,561.18 km) |
| Fort Madison to Obertshausen | 4,532.66 mi (7,294.62 km) |
| Fort Madison to Oberursel | 4,517.95 mi (7,270.94 km) |
| Fort Madison to Ochsenfurt | 4,594.13 mi (7,393.54 km) |
| Fort Madison to Ochsenhausen | 4,653.87 mi (7,489.67 km) |
| Fort Madison to Ochtrup | 4,391.03 mi (7,066.68 km) |
| Fort Madison to Odenthal | 4,432.80 mi (7,133.91 km) |
| Fort Madison to Oelde | 4,439.26 mi (7,144.29 km) |
| Fort Madison to Oelsnitz | 4,637.94 mi (7,464.04 km) |
| Fort Madison to Oer-Erkenschwick | 4,414.49 mi (7,104.43 km) |
