| Falls Church to Oerlinghausen | 4,010.63 mi (6,454.49 km) |
| Falls Church to Oestrich-Winkel | 4,039.75 mi (6,501.35 km) |
| Falls Church to Offenburg | 4,081.62 mi (6,568.73 km) |
| Falls Church to Oftersheim | 4,081.74 mi (6,568.93 km) |
| Falls Church to Ohrdruf | 4,124.45 mi (6,637.66 km) |
| Falls Church to Ohringen | 4,124.05 mi (6,637.01 km) |
| Falls Church to Olbernhau | 4,231.13 mi (6,809.35 km) |
| Falls Church to Olching | 4,229.06 mi (6,806.01 km) |
| Falls Church to Oldenburg | 3,960.98 mi (6,374.58 km) |
| Falls Church to Oldenburg in Holstein | 4,029.50 mi (6,484.85 km) |
| Falls Church to Olfen | 3,967.25 mi (6,384.68 km) |
| Falls Church to Olpe | 4,004.32 mi (6,444.34 km) |
| Falls Church to Olsberg | 4,020.72 mi (6,470.72 km) |
| Falls Church to Oranienburg | 4,162.33 mi (6,698.62 km) |
| Falls Church to Ortenberg | 4,071.89 mi (6,553.08 km) |
