| Manassas to Orbetello | 4,434.80 mi (7,137.13 km) |
| Manassas to Oria | 4,787.67 mi (7,705.01 km) |
| Manassas to Oristano | 4,403.87 mi (7,087.34 km) |
| Manassas to Orta Nova | 4,672.28 mi (7,519.31 km) |
| Manassas to Orte | 4,485.75 mi (7,219.11 km) |
| Manassas to Ortona | 4,577.67 mi (7,367.05 km) |
| Manassas to Orvieto | 4,464.62 mi (7,185.11 km) |
| Manassas to Orzinuovi | 4,279.93 mi (6,887.88 km) |
| Manassas to Osimo | 4,497.46 mi (7,237.96 km) |
| Manassas to Ospitaletto | 4,280.88 mi (6,889.40 km) |
| Manassas to Ostuni | 4,776.52 mi (7,687.07 km) |
| Manassas to Ottaviano | 4,635.85 mi (7,460.68 km) |
| Manassas to Ovada | 4,248.91 mi (6,837.96 km) |
| Manassas to Ozieri | 4,399.43 mi (7,080.19 km) |
| Manassas to Paceco | 4,654.58 mi (7,490.83 km) |
