| Middlesex to Opwijk | 3,675.37 mi (5,914.93 km) |
| Middlesex to Ostend | 3,617.76 mi (5,822.22 km) |
| Middlesex to Oud-Heverlee | 3,698.35 mi (5,951.92 km) |
| Middlesex to Oud-Turnhout | 3,698.68 mi (5,952.45 km) |
| Middlesex to Oudenaarde | 3,654.65 mi (5,881.59 km) |
| Middlesex to Oudenburg | 3,622.06 mi (5,829.14 km) |
| Middlesex to Oupeye | 3,741.11 mi (6,020.73 km) |
| Middlesex to Overijse | 3,694.23 mi (5,945.29 km) |
| Middlesex to Overpelt | 3,718.64 mi (5,984.57 km) |
| Middlesex to Paal | 3,713.45 mi (5,976.22 km) |
| Middlesex to Peer | 3,722.30 mi (5,990.47 km) |
| Middlesex to Pepinster | 3,751.90 mi (6,038.10 km) |
| Middlesex to Peruwelz | 3,662.36 mi (5,894.00 km) |
| Middlesex to Perwez | 3,709.78 mi (5,970.32 km) |
| Middlesex to Philippeville | 3,710.06 mi (5,970.76 km) |
