| Grays to Orbetello | 806.40 mi (1,297.78 km) |
| Grays to Oria | 1,119.56 mi (1,801.76 km) |
| Grays to Oristano | 891.95 mi (1,435.45 km) |
| Grays to Orta Nova | 1,010.24 mi (1,625.82 km) |
| Grays to Orte | 841.12 mi (1,353.65 km) |
| Grays to Ortona | 912.79 mi (1,469.00 km) |
| Grays to Orvieto | 818.43 mi (1,317.14 km) |
| Grays to Orzinuovi | 607.32 mi (977.38 km) |
| Grays to Osimo | 823.69 mi (1,325.60 km) |
| Grays to Ospitaletto | 604.18 mi (972.33 km) |
| Grays to Ostuni | 1,105.80 mi (1,779.62 km) |
| Grays to Ottaviano | 995.23 mi (1,601.67 km) |
| Grays to Ovada | 607.96 mi (978.41 km) |
| Grays to Ozieri | 858.42 mi (1,381.49 km) |
| Grays to Paceco | 1,105.23 mi (1,778.69 km) |
