| Grevena to Novi di Modena | 630.12 mi (1,014.08 km) |
| Grevena to Novi Ligure | 720.06 mi (1,158.82 km) |
| Grevena to Nuoro | 637.95 mi (1,026.68 km) |
| Grevena to Occhiobello | 602.01 mi (968.85 km) |
| Grevena to Oderzo | 598.63 mi (963.41 km) |
| Grevena to Oggiono | 725.62 mi (1,167.77 km) |
| Grevena to Olbia | 628.79 mi (1,011.93 km) |
| Grevena to Oleggio | 750.57 mi (1,207.92 km) |
| Grevena to Olgiate Comasco | 741.91 mi (1,193.99 km) |
| Grevena to Olgiate Olona | 740.76 mi (1,192.14 km) |
| Grevena to Omegna | 768.88 mi (1,237.39 km) |
| Grevena to Opera | 718.60 mi (1,156.48 km) |
| Grevena to Oppeano | 632.05 mi (1,017.18 km) |
| Grevena to Orbassano | 783.21 mi (1,260.45 km) |
| Grevena to Orbetello | 554.51 mi (892.40 km) |
