| Ilmenau to Oestrich-Winkel | 137.12 mi (220.67 km) |
| Ilmenau to Offenburg | 203.36 mi (327.27 km) |
| Ilmenau to Oftersheim | 137.73 mi (221.66 km) |
| Ilmenau to Ohrdruf | 12.88 mi (20.72 km) |
| Ilmenau to Ohringen | 120.39 mi (193.75 km) |
| Ilmenau to Olbernhau | 105.70 mi (170.10 km) |
| Ilmenau to Olching | 172.55 mi (277.69 km) |
| Ilmenau to Oldenburg | 205.36 mi (330.49 km) |
| Ilmenau to Oldenburg in Holstein | 249.85 mi (402.10 km) |
| Ilmenau to Olfen | 168.88 mi (271.79 km) |
| Ilmenau to Olpe | 136.56 mi (219.77 km) |
| Ilmenau to Olsberg | 115.45 mi (185.80 km) |
| Ilmenau to Oranienburg | 174.07 mi (280.13 km) |
| Ilmenau to Ortenberg | 84.97 mi (136.74 km) |
| Ilmenau to Oschatz | 104.24 mi (167.75 km) |
