| Romulus to Octeville | 3,763.97 mi (6,057.53 km) |
| Romulus to Oignies | 3,921.25 mi (6,310.64 km) |
| Romulus to Oissel | 3,882.51 mi (6,248.29 km) |
| Romulus to Olivet | 3,963.28 mi (6,378.28 km) |
| Romulus to Ollioules | 4,295.13 mi (6,912.35 km) |
| Romulus to Olonne-sur-Mer | 3,854.67 mi (6,203.49 km) |
| Romulus to Oloron-Sainte-Marie | 4,016.23 mi (6,463.50 km) |
| Romulus to Onet Village | 4,112.58 mi (6,618.56 km) |
| Romulus to Onnaing | 3,947.37 mi (6,352.68 km) |
| Romulus to Orange | 4,214.22 mi (6,782.14 km) |
| Romulus to Orchies | 3,930.80 mi (6,326.02 km) |
| Romulus to Orleans | 3,962.33 mi (6,376.76 km) |
| Romulus to Orly | 3,953.95 mi (6,363.27 km) |
| Romulus to Ormesson-sur-Marne | 3,958.38 mi (6,370.40 km) |
| Romulus to Orsay | 3,947.24 mi (6,352.46 km) |
