| Grootegast to Orbetello | 778.48 mi (1,252.84 km) |
| Grootegast to Oria | 1,026.57 mi (1,652.10 km) |
| Grootegast to Oristano | 926.08 mi (1,490.38 km) |
| Grootegast to Orta Nova | 930.79 mi (1,497.96 km) |
| Grootegast to Orte | 794.55 mi (1,278.70 km) |
| Grootegast to Ortona | 838.82 mi (1,349.94 km) |
| Grootegast to Orvieto | 773.20 mi (1,244.34 km) |
| Grootegast to Orzinuovi | 564.36 mi (908.26 km) |
| Grootegast to Osimo | 748.49 mi (1,204.57 km) |
| Grootegast to Ospitaletto | 555.92 mi (894.66 km) |
| Grootegast to Ostuni | 1,011.06 mi (1,627.14 km) |
| Grootegast to Ottaviano | 936.10 mi (1,506.50 km) |
| Grootegast to Ovada | 602.19 mi (969.13 km) |
| Grootegast to Ozieri | 882.00 mi (1,419.44 km) |
| Grootegast to Paceco | 1,094.21 mi (1,760.96 km) |
