| Romulus to Oberkirch | 4,185.82 mi (6,736.43 km) |
| Romulus to Obernburg am Main | 4,178.88 mi (6,725.26 km) |
| Romulus to Obernkirchen | 4,091.25 mi (6,584.23 km) |
| Romulus to Oberschleissheim | 4,330.72 mi (6,969.62 km) |
| Romulus to Oberstdorf | 4,313.23 mi (6,941.47 km) |
| Romulus to Obertraubling | 4,325.92 mi (6,961.90 km) |
| Romulus to Obertshausen | 4,159.01 mi (6,693.28 km) |
| Romulus to Oberursel | 4,144.40 mi (6,669.77 km) |
| Romulus to Ochsenfurt | 4,220.86 mi (6,792.82 km) |
| Romulus to Ochsenhausen | 4,275.25 mi (6,880.35 km) |
| Romulus to Ochtrup | 4,022.70 mi (6,473.91 km) |
| Romulus to Odenthal | 4,060.10 mi (6,534.10 km) |
| Romulus to Oelde | 4,070.90 mi (6,551.47 km) |
| Romulus to Oelsnitz | 4,270.48 mi (6,872.67 km) |
| Romulus to Oer-Erkenschwick | 4,044.16 mi (6,508.45 km) |
