| Dumbarton to Oberkirch | 738.86 mi (1,189.07 km) |
| Dumbarton to Obernburg am Main | 708.36 mi (1,140.00 km) |
| Dumbarton to Obernkirchen | 608.58 mi (979.41 km) |
| Dumbarton to Oberschleissheim | 863.60 mi (1,389.82 km) |
| Dumbarton to Oberstdorf | 864.28 mi (1,390.92 km) |
| Dumbarton to Obertraubling | 850.44 mi (1,368.65 km) |
| Dumbarton to Obertshausen | 687.72 mi (1,106.79 km) |
| Dumbarton to Oberursel | 672.96 mi (1,083.03 km) |
| Dumbarton to Ochsenfurt | 748.02 mi (1,203.82 km) |
| Dumbarton to Ochsenhausen | 820.05 mi (1,319.74 km) |
| Dumbarton to Ochtrup | 541.29 mi (871.13 km) |
| Dumbarton to Odenthal | 587.05 mi (944.76 km) |
| Dumbarton to Oelde | 589.52 mi (948.74 km) |
| Dumbarton to Oelsnitz | 788.44 mi (1,268.87 km) |
| Dumbarton to Oer-Erkenschwick | 565.62 mi (910.28 km) |
