| Northolt to Octeville | 143.92 mi (231.61 km) |
| Northolt to Oignies | 164.07 mi (264.04 km) |
| Northolt to Oissel | 165.34 mi (266.09 km) |
| Northolt to Olivet | 273.90 mi (440.81 km) |
| Northolt to Ollioules | 649.16 mi (1,044.73 km) |
| Northolt to Olonne-sur-Mer | 351.96 mi (566.43 km) |
| Northolt to Oloron-Sainte-Marie | 577.21 mi (928.93 km) |
| Northolt to Onet Village | 514.65 mi (828.25 km) |
| Northolt to Onnaing | 190.29 mi (306.24 km) |
| Northolt to Orange | 565.08 mi (909.40 km) |
| Northolt to Orchies | 173.67 mi (279.50 km) |
| Northolt to Orleans | 271.55 mi (437.02 km) |
| Northolt to Orly | 229.02 mi (368.57 km) |
| Northolt to Ormesson-sur-Marne | 230.08 mi (370.28 km) |
| Northolt to Orsay | 227.06 mi (365.43 km) |
