| Ionia to Oerlinghausen | 4,110.99 mi (6,616.00 km) |
| Ionia to Oestrich-Winkel | 4,159.25 mi (6,693.66 km) |
| Ionia to Offenburg | 4,214.43 mi (6,782.47 km) |
| Ionia to Oftersheim | 4,204.84 mi (6,767.04 km) |
| Ionia to Ohrdruf | 4,228.52 mi (6,805.14 km) |
| Ionia to Ohringen | 4,245.73 mi (6,832.84 km) |
| Ionia to Olbernhau | 4,328.40 mi (6,965.88 km) |
| Ionia to Olching | 4,353.15 mi (7,005.72 km) |
| Ionia to Oldenburg | 4,052.13 mi (6,521.27 km) |
| Ionia to Oldenburg in Holstein | 4,102.94 mi (6,603.04 km) |
| Ionia to Olfen | 4,073.50 mi (6,555.67 km) |
| Ionia to Olpe | 4,115.46 mi (6,623.20 km) |
| Ionia to Olsberg | 4,127.03 mi (6,641.81 km) |
| Ionia to Oranienburg | 4,242.39 mi (6,827.47 km) |
| Ionia to Ortenberg | 4,185.12 mi (6,735.31 km) |
