| Ostrow Mazowiecka to Octeville | 1,037.30 mi (1,669.37 km) |
| Ostrow Mazowiecka to Oignies | 824.09 mi (1,326.24 km) |
| Ostrow Mazowiecka to Oissel | 930.81 mi (1,498.00 km) |
| Ostrow Mazowiecka to Olivet | 941.86 mi (1,515.78 km) |
| Ostrow Mazowiecka to Ollioules | 994.42 mi (1,600.37 km) |
| Ostrow Mazowiecka to Olonne-sur-Mer | 1,137.06 mi (1,829.92 km) |
| Ostrow Mazowiecka to Oloron-Sainte-Marie | 1,226.26 mi (1,973.47 km) |
| Ostrow Mazowiecka to Onet Village | 1,052.31 mi (1,693.53 km) |
| Ostrow Mazowiecka to Onnaing | 800.72 mi (1,288.63 km) |
| Ostrow Mazowiecka to Orange | 981.29 mi (1,579.23 km) |
| Ostrow Mazowiecka to Orchies | 813.52 mi (1,309.23 km) |
| Ostrow Mazowiecka to Orleans | 940.24 mi (1,513.17 km) |
| Ostrow Mazowiecka to Orly | 893.97 mi (1,438.71 km) |
| Ostrow Mazowiecka to Ormesson-sur-Marne | 886.75 mi (1,427.08 km) |
| Ostrow Mazowiecka to Orsay | 903.78 mi (1,454.49 km) |
