| Sint-Pieters-Leeuw to Oria | 957.68 mi (1,541.24 km) |
| Sint-Pieters-Leeuw to Oristano | 780.22 mi (1,255.64 km) |
| Sint-Pieters-Leeuw to Orta Nova | 851.54 mi (1,370.41 km) |
| Sint-Pieters-Leeuw to Orte | 691.73 mi (1,113.23 km) |
| Sint-Pieters-Leeuw to Ortona | 754.88 mi (1,214.86 km) |
| Sint-Pieters-Leeuw to Orvieto | 669.22 mi (1,077.01 km) |
| Sint-Pieters-Leeuw to Orzinuovi | 454.83 mi (731.98 km) |
| Sint-Pieters-Leeuw to Osimo | 664.38 mi (1,069.21 km) |
| Sint-Pieters-Leeuw to Ospitaletto | 449.68 mi (723.70 km) |
| Sint-Pieters-Leeuw to Ostuni | 943.35 mi (1,518.18 km) |
| Sint-Pieters-Leeuw to Ottaviano | 843.05 mi (1,356.75 km) |
| Sint-Pieters-Leeuw to Ovada | 470.95 mi (757.92 km) |
| Sint-Pieters-Leeuw to Ozieri | 740.65 mi (1,191.97 km) |
| Sint-Pieters-Leeuw to Paceco | 973.28 mi (1,566.34 km) |
| Sint-Pieters-Leeuw to Pachino | 1,109.91 mi (1,786.22 km) |
