| Gladstone to Orbetello | 5,131.14 mi (8,257.78 km) |
| Gladstone to Oria | 5,469.49 mi (8,802.30 km) |
| Gladstone to Oristano | 5,134.63 mi (8,263.39 km) |
| Gladstone to Orta Nova | 5,356.73 mi (8,620.82 km) |
| Gladstone to Orte | 5,176.36 mi (8,330.55 km) |
| Gladstone to Ortona | 5,259.52 mi (8,464.38 km) |
| Gladstone to Orvieto | 5,154.18 mi (8,294.85 km) |
| Gladstone to Orzinuovi | 4,953.93 mi (7,972.58 km) |
| Gladstone to Osimo | 5,173.33 mi (8,325.67 km) |
| Gladstone to Ospitaletto | 4,952.71 mi (7,970.62 km) |
| Gladstone to Ostuni | 5,456.57 mi (8,781.50 km) |
| Gladstone to Ottaviano | 5,330.73 mi (8,578.98 km) |
| Gladstone to Ovada | 4,936.13 mi (7,943.93 km) |
| Gladstone to Ozieri | 5,122.47 mi (8,243.82 km) |
| Gladstone to Paceco | 5,383.16 mi (8,663.36 km) |
