| Towson to Orbetello | 4,371.25 mi (7,034.84 km) |
| Towson to Oria | 4,723.94 mi (7,602.45 km) |
| Towson to Oristano | 4,341.08 mi (6,986.29 km) |
| Towson to Orta Nova | 4,608.58 mi (7,416.78 km) |
| Towson to Orte | 4,422.10 mi (7,116.68 km) |
| Towson to Ortona | 4,513.90 mi (7,264.42 km) |
| Towson to Orvieto | 4,400.95 mi (7,082.65 km) |
| Towson to Orzinuovi | 4,215.99 mi (6,784.98 km) |
| Towson to Osimo | 4,433.59 mi (7,135.17 km) |
| Towson to Ospitaletto | 4,216.91 mi (6,786.46 km) |
| Towson to Ostuni | 4,712.77 mi (7,584.47 km) |
| Towson to Ottaviano | 4,572.31 mi (7,358.43 km) |
| Towson to Ovada | 4,185.16 mi (6,735.36 km) |
| Towson to Ozieri | 4,336.43 mi (6,978.81 km) |
| Towson to Paceco | 4,591.80 mi (7,389.79 km) |
