| Holyhead to Opole | 973.09 mi (1,566.04 km) |
| Holyhead to Orzesze | 1,019.27 mi (1,640.36 km) |
| Holyhead to Osowa | 940.17 mi (1,513.05 km) |
| Holyhead to Ostroda | 1,006.20 mi (1,619.33 km) |
| Holyhead to Ostroleka | 1,078.71 mi (1,736.01 km) |
| Holyhead to Ostrow Mazowiecka | 1,096.10 mi (1,764.00 km) |
| Holyhead to Ostrow Wielkopolski | 947.64 mi (1,525.08 km) |
| Holyhead to Ostrowiec Swietokrzyski | 1,110.17 mi (1,786.65 km) |
| Holyhead to Ostrzeszow | 956.96 mi (1,540.08 km) |
| Holyhead to Oswiecim | 1,041.55 mi (1,676.20 km) |
| Holyhead to Otwock | 1,081.24 mi (1,740.09 km) |
| Holyhead to Ozarow Mazowiecki | 1,060.36 mi (1,706.49 km) |
| Holyhead to Ozimek | 984.49 mi (1,584.39 km) |
| Holyhead to Ozorkow | 1,002.33 mi (1,613.10 km) |
| Holyhead to Pabianice | 1,012.25 mi (1,629.05 km) |
