| Towson to Oerlinghausen | 3,964.78 mi (6,380.70 km) |
| Towson to Oestrich-Winkel | 3,994.15 mi (6,427.96 km) |
| Towson to Offenburg | 4,036.24 mi (6,495.70 km) |
| Towson to Oftersheim | 4,036.20 mi (6,495.63 km) |
| Towson to Ohrdruf | 4,078.65 mi (6,563.96 km) |
| Towson to Ohringen | 4,078.49 mi (6,563.69 km) |
| Towson to Olbernhau | 4,185.27 mi (6,735.55 km) |
| Towson to Olching | 4,183.55 mi (6,732.78 km) |
| Towson to Oldenburg | 3,915.04 mi (6,300.65 km) |
| Towson to Oldenburg in Holstein | 3,983.44 mi (6,410.72 km) |
| Towson to Olfen | 3,921.47 mi (6,310.99 km) |
| Towson to Olpe | 3,958.60 mi (6,370.75 km) |
| Towson to Olsberg | 3,974.94 mi (6,397.04 km) |
| Towson to Oranienburg | 4,116.31 mi (6,624.57 km) |
| Towson to Ortenberg | 4,026.21 mi (6,479.55 km) |
