| Gourock to Opole | 1,002.03 mi (1,612.61 km) |
| Gourock to Orzesze | 1,051.20 mi (1,691.75 km) |
| Gourock to Osowa | 920.12 mi (1,480.79 km) |
| Gourock to Ostroda | 993.11 mi (1,598.25 km) |
| Gourock to Ostroleka | 1,070.08 mi (1,722.13 km) |
| Gourock to Ostrow Mazowiecka | 1,089.80 mi (1,753.87 km) |
| Gourock to Ostrow Wielkopolski | 965.18 mi (1,553.30 km) |
| Gourock to Ostrowiec Swietokrzyski | 1,125.38 mi (1,811.12 km) |
| Gourock to Ostrzeszow | 977.00 mi (1,572.32 km) |
| Gourock to Oswiecim | 1,073.06 mi (1,726.92 km) |
| Gourock to Otwock | 1,084.00 mi (1,744.53 km) |
| Gourock to Ozarow Mazowiecki | 1,063.13 mi (1,710.95 km) |
| Gourock to Ozimek | 1,012.41 mi (1,629.31 km) |
| Gourock to Ozorkow | 1,011.87 mi (1,628.44 km) |
| Gourock to Pabianice | 1,025.24 mi (1,649.97 km) |
