| Castelo Branco to Opole | 1,435.85 mi (2,310.78 km) |
| Castelo Branco to Orzesze | 1,457.10 mi (2,344.97 km) |
| Castelo Branco to Osowa | 1,568.39 mi (2,524.08 km) |
| Castelo Branco to Ostroda | 1,599.00 mi (2,573.34 km) |
| Castelo Branco to Ostroleka | 1,641.56 mi (2,641.84 km) |
| Castelo Branco to Ostrow Mazowiecka | 1,647.67 mi (2,651.66 km) |
| Castelo Branco to Ostrow Wielkopolski | 1,457.58 mi (2,345.75 km) |
| Castelo Branco to Ostrowiec Swietokrzyski | 1,584.60 mi (2,550.17 km) |
| Castelo Branco to Ostrzeszow | 1,455.70 mi (2,342.72 km) |
| Castelo Branco to Oswiecim | 1,474.39 mi (2,372.80 km) |
| Castelo Branco to Otwock | 1,605.96 mi (2,584.54 km) |
| Castelo Branco to Ozarow Mazowiecki | 1,589.95 mi (2,558.78 km) |
| Castelo Branco to Ozimek | 1,447.42 mi (2,329.39 km) |
| Castelo Branco to Ozorkow | 1,523.79 mi (2,452.31 km) |
| Castelo Branco to Pabianice | 1,519.41 mi (2,445.26 km) |
