| Groningen to Orbetello | 774.77 mi (1,246.88 km) |
| Groningen to Oria | 1,019.79 mi (1,641.19 km) |
| Groningen to Oristano | 924.61 mi (1,488.02 km) |
| Groningen to Orta Nova | 924.67 mi (1,488.11 km) |
| Groningen to Orte | 790.03 mi (1,271.43 km) |
| Groningen to Ortona | 833.08 mi (1,340.71 km) |
| Groningen to Orvieto | 768.79 mi (1,237.25 km) |
| Groningen to Orzinuovi | 560.81 mi (902.53 km) |
| Groningen to Osimo | 742.90 mi (1,195.59 km) |
| Groningen to Ospitaletto | 552.17 mi (888.64 km) |
| Groningen to Ostuni | 1,004.23 mi (1,616.15 km) |
| Groningen to Ottaviano | 930.78 mi (1,497.95 km) |
| Groningen to Ovada | 600.05 mi (965.69 km) |
| Groningen to Ozieri | 880.18 mi (1,416.52 km) |
| Groningen to Paceco | 1,090.59 mi (1,755.14 km) |
