| Ironton to Oerlinghausen | 4,239.30 mi (6,822.50 km) |
| Ironton to Oestrich-Winkel | 4,275.75 mi (6,881.15 km) |
| Ironton to Offenburg | 4,322.59 mi (6,956.54 km) |
| Ironton to Oftersheim | 4,319.17 mi (6,951.04 km) |
| Ironton to Ohrdruf | 4,354.82 mi (7,008.41 km) |
| Ironton to Ohringen | 4,361.05 mi (7,018.44 km) |
| Ironton to Olbernhau | 4,459.13 mi (7,176.28 km) |
| Ironton to Olching | 4,467.19 mi (7,189.25 km) |
| Ironton to Oldenburg | 4,185.93 mi (6,736.60 km) |
| Ironton to Oldenburg in Holstein | 4,247.53 mi (6,835.74 km) |
| Ironton to Olfen | 4,198.08 mi (6,756.15 km) |
| Ironton to Olpe | 4,237.10 mi (6,818.95 km) |
| Ironton to Olsberg | 4,251.70 mi (6,842.45 km) |
| Ironton to Oranienburg | 4,383.37 mi (7,054.35 km) |
| Ironton to Ortenberg | 4,305.62 mi (6,929.23 km) |
