| Ostrow Mazowiecka to Olivenza | 1,686.33 mi (2,713.89 km) |
| Ostrow Mazowiecka to Olot | 1,159.49 mi (1,866.03 km) |
| Ostrow Mazowiecka to Onate | 1,303.24 mi (2,097.37 km) |
| Ostrow Mazowiecka to Onda | 1,369.43 mi (2,203.88 km) |
| Ostrow Mazowiecka to Onteniente | 1,440.65 mi (2,318.49 km) |
| Ostrow Mazowiecka to Orihuela | 1,491.41 mi (2,400.20 km) |
| Ostrow Mazowiecka to Osuna | 1,684.26 mi (2,710.55 km) |
| Ostrow Mazowiecka to Ourense | 1,549.06 mi (2,492.97 km) |
| Ostrow Mazowiecka to Oviedo | 1,424.90 mi (2,293.16 km) |
| Ostrow Mazowiecka to Paiporta | 1,402.42 mi (2,256.98 km) |
| Ostrow Mazowiecka to Pajara | 2,489.47 mi (4,006.41 km) |
| Ostrow Mazowiecka to Palafolls | 1,176.02 mi (1,892.63 km) |
| Ostrow Mazowiecka to Palafrugell | 1,149.01 mi (1,849.15 km) |
| Ostrow Mazowiecka to Palamos | 1,153.84 mi (1,856.93 km) |
| Ostrow Mazowiecka to Palencia | 1,430.94 mi (2,302.87 km) |
