| Grottammare to Oerlinghausen | 665.65 mi (1,071.25 km) |
| Grottammare to Oestrich-Winkel | 558.57 mi (898.93 km) |
| Grottammare to Offenburg | 474.11 mi (763.01 km) |
| Grottammare to Oftersheim | 507.84 mi (817.28 km) |
| Grottammare to Ohrdruf | 561.27 mi (903.28 km) |
| Grottammare to Ohringen | 477.16 mi (767.92 km) |
| Grottammare to Olbernhau | 531.02 mi (854.60 km) |
| Grottammare to Olching | 380.45 mi (612.27 km) |
| Grottammare to Oldenburg | 747.97 mi (1,203.73 km) |
| Grottammare to Oldenburg in Holstein | 793.05 mi (1,276.29 km) |
| Grottammare to Olfen | 674.39 mi (1,085.32 km) |
| Grottammare to Olpe | 622.70 mi (1,002.14 km) |
| Grottammare to Olsberg | 630.12 mi (1,014.08 km) |
| Grottammare to Oranienburg | 675.30 mi (1,086.79 km) |
| Grottammare to Ortenberg | 557.41 mi (897.07 km) |
