| Dumbarton to Oerlinghausen | 602.94 mi (970.35 km) |
| Dumbarton to Oestrich-Winkel | 663.43 mi (1,067.68 km) |
| Dumbarton to Offenburg | 737.81 mi (1,187.39 km) |
| Dumbarton to Oftersheim | 712.40 mi (1,146.50 km) |
| Dumbarton to Ohrdruf | 720.73 mi (1,159.90 km) |
| Dumbarton to Ohringen | 750.20 mi (1,207.34 km) |
| Dumbarton to Olbernhau | 820.98 mi (1,321.25 km) |
| Dumbarton to Olching | 857.77 mi (1,380.45 km) |
| Dumbarton to Oldenburg | 546.68 mi (879.79 km) |
| Dumbarton to Oldenburg in Holstein | 619.56 mi (997.09 km) |
| Dumbarton to Olfen | 567.18 mi (912.79 km) |
| Dumbarton to Olpe | 611.89 mi (984.74 km) |
| Dumbarton to Olsberg | 620.35 mi (998.35 km) |
| Dumbarton to Oranienburg | 747.71 mi (1,203.32 km) |
| Dumbarton to Ortenberg | 682.20 mi (1,097.89 km) |
