| Helensburgh to Octeville | 459.83 mi (740.03 km) |
| Helensburgh to Oignies | 498.37 mi (802.05 km) |
| Helensburgh to Oissel | 521.32 mi (838.98 km) |
| Helensburgh to Olivet | 629.52 mi (1,013.12 km) |
| Helensburgh to Ollioules | 1,005.51 mi (1,618.21 km) |
| Helensburgh to Olonne-sur-Mer | 667.26 mi (1,073.85 km) |
| Helensburgh to Oloron-Sainte-Marie | 904.59 mi (1,455.80 km) |
| Helensburgh to Onet Village | 866.64 mi (1,394.72 km) |
| Helensburgh to Onnaing | 519.04 mi (835.31 km) |
| Helensburgh to Orange | 921.40 mi (1,482.85 km) |
| Helensburgh to Orchies | 504.73 mi (812.28 km) |
| Helensburgh to Orleans | 627.25 mi (1,009.46 km) |
| Helensburgh to Orly | 584.83 mi (941.19 km) |
| Helensburgh to Ormesson-sur-Marne | 585.43 mi (942.16 km) |
| Helensburgh to Orsay | 583.28 mi (938.70 km) |
