| Grande-Synthe to Oria | 1,032.38 mi (1,661.46 km) |
| Grande-Synthe to Oristano | 825.04 mi (1,327.78 km) |
| Grande-Synthe to Orta Nova | 924.15 mi (1,487.27 km) |
| Grande-Synthe to Orte | 758.34 mi (1,220.44 km) |
| Grande-Synthe to Ortona | 826.90 mi (1,330.77 km) |
| Grande-Synthe to Orvieto | 735.69 mi (1,183.97 km) |
| Grande-Synthe to Orzinuovi | 522.81 mi (841.39 km) |
| Grande-Synthe to Osimo | 737.19 mi (1,186.39 km) |
| Grande-Synthe to Ospitaletto | 518.95 mi (835.17 km) |
| Grande-Synthe to Ostuni | 1,018.41 mi (1,638.98 km) |
| Grande-Synthe to Ottaviano | 911.60 mi (1,467.08 km) |
| Grande-Synthe to Ovada | 529.27 mi (851.77 km) |
| Grande-Synthe to Ozieri | 788.76 mi (1,269.38 km) |
| Grande-Synthe to Paceco | 1,030.04 mi (1,657.69 km) |
| Grande-Synthe to Pachino | 1,171.93 mi (1,886.04 km) |
