| Romanshorn to Octeville | 521.92 mi (839.95 km) |
| Romanshorn to Oignies | 351.14 mi (565.11 km) |
| Romanshorn to Oissel | 397.93 mi (640.41 km) |
| Romanshorn to Olivet | 347.09 mi (558.59 km) |
| Romanshorn to Ollioules | 349.88 mi (563.07 km) |
| Romanshorn to Olonne-sur-Mer | 528.25 mi (850.14 km) |
| Romanshorn to Oloron-Sainte-Marie | 569.37 mi (916.31 km) |
| Romanshorn to Onet Village | 392.60 mi (631.83 km) |
| Romanshorn to Onnaing | 325.85 mi (524.40 km) |
| Romanshorn to Orange | 322.20 mi (518.53 km) |
| Romanshorn to Orchies | 342.11 mi (550.57 km) |
| Romanshorn to Orleans | 346.75 mi (558.03 km) |
| Romanshorn to Orly | 331.05 mi (532.77 km) |
| Romanshorn to Ormesson-sur-Marne | 325.18 mi (523.32 km) |
| Romanshorn to Orsay | 339.62 mi (546.57 km) |
