| Rockville Centre to Orbetello | 4,191.32 mi (6,745.27 km) |
| Rockville Centre to Oria | 4,544.28 mi (7,313.32 km) |
| Rockville Centre to Oristano | 4,160.65 mi (6,695.91 km) |
| Rockville Centre to Orta Nova | 4,428.88 mi (7,127.59 km) |
| Rockville Centre to Orte | 4,242.30 mi (6,827.33 km) |
| Rockville Centre to Ortona | 4,334.32 mi (6,975.41 km) |
| Rockville Centre to Orvieto | 4,221.19 mi (6,793.35 km) |
| Rockville Centre to Orzinuovi | 4,036.81 mi (6,496.62 km) |
| Rockville Centre to Osimo | 4,254.23 mi (6,846.52 km) |
| Rockville Centre to Ospitaletto | 4,037.81 mi (6,498.23 km) |
| Rockville Centre to Ostuni | 4,533.16 mi (7,295.42 km) |
| Rockville Centre to Ottaviano | 4,392.36 mi (7,068.82 km) |
| Rockville Centre to Ovada | 4,005.55 mi (6,446.31 km) |
| Rockville Centre to Ozieri | 4,156.05 mi (6,688.52 km) |
| Rockville Centre to Paceco | 4,411.37 mi (7,099.41 km) |
