| Ostrow Mazowiecka to Nuth | 694.22 mi (1,117.23 km) |
| Ostrow Mazowiecka to Oegstgeest | 732.84 mi (1,179.39 km) |
| Ostrow Mazowiecka to Oirschot | 707.86 mi (1,139.19 km) |
| Ostrow Mazowiecka to Oisterwijk | 710.68 mi (1,143.74 km) |
| Ostrow Mazowiecka to Oldebroek | 670.12 mi (1,078.45 km) |
| Ostrow Mazowiecka to Oldenzaal | 628.43 mi (1,011.36 km) |
| Ostrow Mazowiecka to Ommen | 647.94 mi (1,042.76 km) |
| Ostrow Mazowiecka to Oosterend | 658.69 mi (1,060.06 km) |
| Ostrow Mazowiecka to Oosterhout | 724.07 mi (1,165.28 km) |
| Ostrow Mazowiecka to Oosterwolde | 649.45 mi (1,045.19 km) |
| Ostrow Mazowiecka to Oostzaan | 712.63 mi (1,146.86 km) |
| Ostrow Mazowiecka to Opmeer | 707.27 mi (1,138.24 km) |
| Ostrow Mazowiecka to Oss | 694.64 mi (1,117.91 km) |
| Ostrow Mazowiecka to Oud-Beijerland | 740.54 mi (1,191.79 km) |
| Ostrow Mazowiecka to Oudenbosch | 738.83 mi (1,189.04 km) |
