| South Portland to Octeville | 3,168.70 mi (5,099.54 km) |
| South Portland to Oignies | 3,339.97 mi (5,375.16 km) |
| South Portland to Oissel | 3,290.38 mi (5,295.35 km) |
| South Portland to Olivet | 3,363.78 mi (5,413.48 km) |
| South Portland to Ollioules | 3,679.03 mi (5,920.82 km) |
| South Portland to Olonne-sur-Mer | 3,241.09 mi (5,216.02 km) |
| South Portland to Oloron-Sainte-Marie | 3,388.44 mi (5,453.16 km) |
| South Portland to Onet Village | 3,495.90 mi (5,626.11 km) |
| South Portland to Onnaing | 3,366.74 mi (5,418.24 km) |
| South Portland to Orange | 3,600.73 mi (5,794.82 km) |
| South Portland to Orchies | 3,350.05 mi (5,391.38 km) |
| South Portland to Orleans | 3,363.08 mi (5,412.35 km) |
| South Portland to Orly | 3,360.61 mi (5,408.38 km) |
| South Portland to Ormesson-sur-Marne | 3,365.58 mi (5,416.37 km) |
| South Portland to Orsay | 3,353.23 mi (5,396.50 km) |
