| Reston to Orbetello | 4,420.75 mi (7,114.51 km) |
| Reston to Oria | 4,773.50 mi (7,682.20 km) |
| Reston to Oristano | 4,390.29 mi (7,065.49 km) |
| Reston to Orta Nova | 4,658.12 mi (7,496.52 km) |
| Reston to Orte | 4,471.63 mi (7,196.40 km) |
| Reston to Ortona | 4,563.46 mi (7,344.18 km) |
| Reston to Orvieto | 4,450.49 mi (7,162.37 km) |
| Reston to Orzinuovi | 4,265.59 mi (6,864.80 km) |
| Reston to Osimo | 4,483.17 mi (7,214.97 km) |
| Reston to Ospitaletto | 4,266.51 mi (6,866.28 km) |
| Reston to Ostuni | 4,762.33 mi (7,664.23 km) |
| Reston to Ottaviano | 4,621.81 mi (7,438.09 km) |
| Reston to Ovada | 4,234.72 mi (6,815.12 km) |
| Reston to Ozieri | 4,385.73 mi (7,058.15 km) |
| Reston to Paceco | 4,641.01 mi (7,468.98 km) |
