| Hemel Hempstead to Octeville | 155.60 mi (250.41 km) |
| Hemel Hempstead to Oignies | 174.40 mi (280.67 km) |
| Hemel Hempstead to Oissel | 180.09 mi (289.83 km) |
| Hemel Hempstead to Olivet | 288.67 mi (464.58 km) |
| Hemel Hempstead to Ollioules | 663.68 mi (1,068.08 km) |
| Hemel Hempstead to Olonne-sur-Mer | 365.19 mi (587.72 km) |
| Hemel Hempstead to Oloron-Sainte-Marie | 591.36 mi (951.71 km) |
| Hemel Hempstead to Onet Village | 529.50 mi (852.15 km) |
| Hemel Hempstead to Onnaing | 200.15 mi (322.10 km) |
| Hemel Hempstead to Orange | 579.68 mi (932.91 km) |
| Hemel Hempstead to Orchies | 183.65 mi (295.56 km) |
| Hemel Hempstead to Orleans | 286.32 mi (460.78 km) |
| Hemel Hempstead to Orly | 243.27 mi (391.51 km) |
| Hemel Hempstead to Ormesson-sur-Marne | 244.21 mi (393.01 km) |
| Hemel Hempstead to Orsay | 241.48 mi (388.62 km) |
