| Langley Park to Orbetello | 4,403.05 mi (7,086.02 km) |
| Langley Park to Oria | 4,755.95 mi (7,653.97 km) |
| Langley Park to Oristano | 4,372.07 mi (7,036.17 km) |
| Langley Park to Orta Nova | 4,640.56 mi (7,468.26 km) |
| Langley Park to Orte | 4,454.01 mi (7,168.04 km) |
| Langley Park to Ortona | 4,545.96 mi (7,316.02 km) |
| Langley Park to Orvieto | 4,432.89 mi (7,134.04 km) |
| Langley Park to Orzinuovi | 4,248.27 mi (6,836.94 km) |
| Langley Park to Osimo | 4,465.78 mi (7,186.98 km) |
| Langley Park to Ospitaletto | 4,249.23 mi (6,838.48 km) |
| Langley Park to Ostuni | 4,744.81 mi (7,636.04 km) |
| Langley Park to Ottaviano | 4,604.10 mi (7,409.58 km) |
| Langley Park to Ovada | 4,217.20 mi (6,786.93 km) |
| Langley Park to Ozieri | 4,367.63 mi (7,029.01 km) |
| Langley Park to Paceco | 4,622.78 mi (7,439.65 km) |
