| Constanta to Octeville | 1,467.38 mi (2,361.52 km) |
| Constanta to Oignies | 1,269.77 mi (2,043.49 km) |
| Constanta to Oissel | 1,343.55 mi (2,162.24 km) |
| Constanta to Olivet | 1,301.02 mi (2,093.79 km) |
| Constanta to Ollioules | 1,137.68 mi (1,830.91 km) |
| Constanta to Olonne-sur-Mer | 1,476.19 mi (2,375.70 km) |
| Constanta to Oloron-Sainte-Marie | 1,454.91 mi (2,341.45 km) |
| Constanta to Onet Village | 1,283.01 mi (2,064.81 km) |
| Constanta to Onnaing | 1,242.58 mi (1,999.75 km) |
| Constanta to Orange | 1,176.86 mi (1,893.98 km) |
| Constanta to Orchies | 1,258.99 mi (2,026.15 km) |
| Constanta to Orleans | 1,300.70 mi (2,093.27 km) |
| Constanta to Orly | 1,281.46 mi (2,062.30 km) |
| Constanta to Ormesson-sur-Marne | 1,275.08 mi (2,052.04 km) |
| Constanta to Orsay | 1,290.56 mi (2,076.95 km) |
