| Ostrow Mazowiecka to Oberkirch | 671.60 mi (1,080.83 km) |
| Ostrow Mazowiecka to Obernburg am Main | 586.69 mi (944.19 km) |
| Ostrow Mazowiecka to Obernkirchen | 537.78 mi (865.47 km) |
| Ostrow Mazowiecka to Oberschleissheim | 551.30 mi (887.23 km) |
| Ostrow Mazowiecka to Oberstdorf | 634.30 mi (1,020.81 km) |
| Ostrow Mazowiecka to Obertraubling | 499.56 mi (803.97 km) |
| Ostrow Mazowiecka to Obertshausen | 592.68 mi (953.83 km) |
| Ostrow Mazowiecka to Oberursel | 599.43 mi (964.69 km) |
| Ostrow Mazowiecka to Ochsenfurt | 555.53 mi (894.03 km) |
| Ostrow Mazowiecka to Ochsenhausen | 618.00 mi (994.57 km) |
| Ostrow Mazowiecka to Ochtrup | 618.95 mi (996.10 km) |
| Ostrow Mazowiecka to Odenthal | 640.53 mi (1,030.83 km) |
| Ostrow Mazowiecka to Oelde | 583.67 mi (939.33 km) |
| Ostrow Mazowiecka to Oelsnitz | 448.49 mi (721.78 km) |
| Ostrow Mazowiecka to Oer-Erkenschwick | 624.09 mi (1,004.38 km) |
