| Dumbarton to Opole | 992.49 mi (1,597.26 km) |
| Dumbarton to Orzesze | 1,041.69 mi (1,676.43 km) |
| Dumbarton to Osowa | 910.45 mi (1,465.23 km) |
| Dumbarton to Ostroda | 983.42 mi (1,582.66 km) |
| Dumbarton to Ostroleka | 1,060.39 mi (1,706.53 km) |
| Dumbarton to Ostrow Mazowiecka | 1,080.11 mi (1,738.26 km) |
| Dumbarton to Ostrow Wielkopolski | 955.55 mi (1,537.81 km) |
| Dumbarton to Ostrowiec Swietokrzyski | 1,115.72 mi (1,795.58 km) |
| Dumbarton to Ostrzeszow | 967.39 mi (1,556.86 km) |
| Dumbarton to Oswiecim | 1,063.53 mi (1,711.59 km) |
| Dumbarton to Otwock | 1,074.31 mi (1,728.93 km) |
| Dumbarton to Ozarow Mazowiecki | 1,053.44 mi (1,695.35 km) |
| Dumbarton to Ozimek | 1,002.86 mi (1,613.95 km) |
| Dumbarton to Ozorkow | 1,002.20 mi (1,612.88 km) |
| Dumbarton to Pabianice | 1,015.58 mi (1,634.42 km) |
