| Potters Bar to Opole | 785.82 mi (1,264.65 km) |
| Potters Bar to Orzesze | 829.11 mi (1,334.32 km) |
| Potters Bar to Osowa | 794.57 mi (1,278.74 km) |
| Potters Bar to Ostroda | 851.96 mi (1,371.10 km) |
| Potters Bar to Ostroleka | 918.55 mi (1,478.26 km) |
| Potters Bar to Ostrow Mazowiecka | 933.53 mi (1,502.37 km) |
| Potters Bar to Ostrow Wielkopolski | 769.28 mi (1,238.03 km) |
| Potters Bar to Ostrowiec Swietokrzyski | 930.16 mi (1,496.95 km) |
| Potters Bar to Ostrzeszow | 776.47 mi (1,249.61 km) |
| Potters Bar to Oswiecim | 851.29 mi (1,370.02 km) |
| Potters Bar to Otwock | 911.44 mi (1,466.83 km) |
| Potters Bar to Ozarow Mazowiecki | 891.02 mi (1,433.96 km) |
| Potters Bar to Ozimek | 797.70 mi (1,283.77 km) |
| Potters Bar to Ozorkow | 828.88 mi (1,333.95 km) |
| Potters Bar to Pabianice | 835.85 mi (1,345.17 km) |
