| Siedlce to Orbetello | 846.56 mi (1,362.41 km) |
| Siedlce to Oria | 835.35 mi (1,344.37 km) |
| Siedlce to Oristano | 1,067.70 mi (1,718.30 km) |
| Siedlce to Orta Nova | 809.63 mi (1,302.97 km) |
| Siedlce to Orte | 813.29 mi (1,308.86 km) |
| Siedlce to Ortona | 771.05 mi (1,240.88 km) |
| Siedlce to Orvieto | 805.50 mi (1,296.33 km) |
| Siedlce to Orzinuovi | 729.05 mi (1,173.29 km) |
| Siedlce to Osimo | 724.13 mi (1,165.37 km) |
| Siedlce to Ospitaletto | 716.71 mi (1,153.43 km) |
| Siedlce to Ostuni | 820.33 mi (1,320.20 km) |
| Siedlce to Ottaviano | 864.01 mi (1,390.49 km) |
| Siedlce to Ovada | 810.72 mi (1,304.73 km) |
| Siedlce to Ozieri | 1,016.57 mi (1,636.00 km) |
| Siedlce to Paceco | 1,086.38 mi (1,748.36 km) |
