| Takoma Park to Oerlinghausen | 3,999.34 mi (6,436.31 km) |
| Takoma Park to Oestrich-Winkel | 4,028.40 mi (6,483.09 km) |
| Takoma Park to Offenburg | 4,070.24 mi (6,550.43 km) |
| Takoma Park to Oftersheim | 4,070.38 mi (6,550.65 km) |
| Takoma Park to Ohrdruf | 4,113.14 mi (6,619.46 km) |
| Takoma Park to Ohringen | 4,112.69 mi (6,618.74 km) |
| Takoma Park to Olbernhau | 4,219.84 mi (6,791.17 km) |
| Takoma Park to Olching | 4,217.70 mi (6,787.72 km) |
| Takoma Park to Oldenburg | 3,949.72 mi (6,356.46 km) |
| Takoma Park to Oldenburg in Holstein | 4,018.31 mi (6,466.84 km) |
| Takoma Park to Olfen | 3,955.94 mi (6,366.47 km) |
| Takoma Park to Olpe | 3,993.00 mi (6,426.11 km) |
| Takoma Park to Olsberg | 4,009.40 mi (6,452.51 km) |
| Takoma Park to Oranienburg | 4,151.10 mi (6,680.55 km) |
| Takoma Park to Ortenberg | 4,060.56 mi (6,534.84 km) |
