| Serres to Opwijk | 1,147.28 mi (1,846.37 km) |
| Serres to Ostend | 1,204.06 mi (1,937.75 km) |
| Serres to Oud-Heverlee | 1,124.40 mi (1,809.54 km) |
| Serres to Oud-Turnhout | 1,129.50 mi (1,817.75 km) |
| Serres to Oudenaarde | 1,165.83 mi (1,876.22 km) |
| Serres to Oudenburg | 1,199.61 mi (1,930.58 km) |
| Serres to Oupeye | 1,083.18 mi (1,743.21 km) |
| Serres to Overijse | 1,127.79 mi (1,815.00 km) |
| Serres to Overpelt | 1,109.93 mi (1,786.26 km) |
| Serres to Paal | 1,112.53 mi (1,790.44 km) |
| Serres to Peer | 1,105.51 mi (1,779.14 km) |
| Serres to Pepinster | 1,071.63 mi (1,724.62 km) |
| Serres to Peruwelz | 1,155.98 mi (1,860.38 km) |
| Serres to Perwez | 1,111.67 mi (1,789.05 km) |
| Serres to Philippeville | 1,108.08 mi (1,783.29 km) |
