| Mainz to Octeville | 442.26 mi (711.75 km) |
| Mainz to Oignies | 235.44 mi (378.90 km) |
| Mainz to Oissel | 323.82 mi (521.14 km) |
| Mainz to Olivet | 323.85 mi (521.18 km) |
| Mainz to Ollioules | 486.57 mi (783.06 km) |
| Mainz to Olonne-sur-Mer | 519.02 mi (835.29 km) |
| Mainz to Oloron-Sainte-Marie | 629.66 mi (1,013.34 km) |
| Mainz to Onet Village | 470.50 mi (757.19 km) |
| Mainz to Onnaing | 208.39 mi (335.37 km) |
| Mainz to Orange | 435.27 mi (700.51 km) |
| Mainz to Orchies | 224.53 mi (361.35 km) |
| Mainz to Orleans | 322.21 mi (518.55 km) |
| Mainz to Orly | 277.75 mi (446.99 km) |
| Mainz to Ormesson-sur-Marne | 270.53 mi (435.38 km) |
| Mainz to Orsay | 287.62 mi (462.89 km) |
