| Falls Church to Orbetello | 4,415.77 mi (7,106.49 km) |
| Falls Church to Oria | 4,768.67 mi (7,674.43 km) |
| Falls Church to Oristano | 4,384.76 mi (7,056.59 km) |
| Falls Church to Orta Nova | 4,653.27 mi (7,488.72 km) |
| Falls Church to Orte | 4,466.73 mi (7,188.50 km) |
| Falls Church to Ortona | 4,558.67 mi (7,336.48 km) |
| Falls Church to Orvieto | 4,445.60 mi (7,154.51 km) |
| Falls Church to Orzinuovi | 4,260.98 mi (6,857.38 km) |
| Falls Church to Osimo | 4,478.49 mi (7,207.43 km) |
| Falls Church to Ospitaletto | 4,261.94 mi (6,858.92 km) |
| Falls Church to Ostuni | 4,757.53 mi (7,656.50 km) |
| Falls Church to Ottaviano | 4,616.81 mi (7,430.04 km) |
| Falls Church to Ovada | 4,229.91 mi (6,807.38 km) |
| Falls Church to Ozieri | 4,380.33 mi (7,049.45 km) |
| Falls Church to Paceco | 4,635.47 mi (7,460.07 km) |
