| Greenbelt to Octeville | 3,633.14 mi (5,846.97 km) |
| Greenbelt to Oignies | 3,806.60 mi (6,126.13 km) |
| Greenbelt to Oissel | 3,755.30 mi (6,043.57 km) |
| Greenbelt to Olivet | 3,827.01 mi (6,158.98 km) |
| Greenbelt to Ollioules | 4,136.53 mi (6,657.10 km) |
| Greenbelt to Olonne-sur-Mer | 3,700.30 mi (5,955.06 km) |
| Greenbelt to Oloron-Sainte-Marie | 3,841.05 mi (6,181.58 km) |
| Greenbelt to Onet Village | 3,953.49 mi (6,362.53 km) |
| Greenbelt to Onnaing | 3,833.43 mi (6,169.31 km) |
| Greenbelt to Orange | 4,059.37 mi (6,532.92 km) |
| Greenbelt to Orchies | 3,816.74 mi (6,142.45 km) |
| Greenbelt to Orleans | 3,826.37 mi (6,157.94 km) |
| Greenbelt to Orly | 3,825.21 mi (6,156.08 km) |
| Greenbelt to Ormesson-sur-Marne | 3,830.28 mi (6,164.24 km) |
| Greenbelt to Orsay | 3,817.70 mi (6,143.99 km) |
