| Grevena to Opwijk | 1,118.36 mi (1,799.83 km) |
| Grevena to Ostend | 1,173.65 mi (1,888.81 km) |
| Grevena to Oud-Heverlee | 1,095.89 mi (1,763.66 km) |
| Grevena to Oud-Turnhout | 1,105.12 mi (1,778.52 km) |
| Grevena to Oudenaarde | 1,134.63 mi (1,826.01 km) |
| Grevena to Oudenburg | 1,169.12 mi (1,881.52 km) |
| Grevena to Oupeye | 1,056.63 mi (1,700.48 km) |
| Grevena to Overijse | 1,098.58 mi (1,767.99 km) |
| Grevena to Overpelt | 1,086.16 mi (1,748.00 km) |
| Grevena to Paal | 1,086.85 mi (1,749.11 km) |
| Grevena to Peer | 1,081.28 mi (1,740.16 km) |
| Grevena to Pepinster | 1,044.62 mi (1,681.15 km) |
| Grevena to Peruwelz | 1,122.51 mi (1,806.50 km) |
| Grevena to Perwez | 1,082.14 mi (1,741.54 km) |
| Grevena to Philippeville | 1,074.90 mi (1,729.89 km) |
