| Gahanna to Oerlinghausen | 4,173.17 mi (6,716.06 km) |
| Gahanna to Oestrich-Winkel | 4,212.74 mi (6,779.75 km) |
| Gahanna to Offenburg | 4,261.83 mi (6,858.76 km) |
| Gahanna to Oftersheim | 4,256.77 mi (6,850.61 km) |
| Gahanna to Ohrdruf | 4,289.29 mi (6,902.95 km) |
| Gahanna to Ohringen | 4,298.42 mi (6,917.64 km) |
| Gahanna to Olbernhau | 4,392.53 mi (7,069.09 km) |
| Gahanna to Olching | 4,404.98 mi (7,089.12 km) |
| Gahanna to Oldenburg | 4,118.33 mi (6,627.81 km) |
| Gahanna to Oldenburg in Holstein | 4,177.22 mi (6,722.58 km) |
| Gahanna to Olfen | 4,132.88 mi (6,651.23 km) |
| Gahanna to Olpe | 4,172.71 mi (6,715.32 km) |
| Gahanna to Olsberg | 4,186.52 mi (6,737.56 km) |
| Gahanna to Oranienburg | 4,314.07 mi (6,942.83 km) |
| Gahanna to Ortenberg | 4,241.58 mi (6,826.16 km) |
