| Ottumwa to Oerlinghausen | 4,469.40 mi (7,192.81 km) |
| Ottumwa to Oestrich-Winkel | 4,523.99 mi (7,280.66 km) |
| Ottumwa to Offenburg | 4,583.24 mi (7,376.01 km) |
| Ottumwa to Oftersheim | 4,570.57 mi (7,355.63 km) |
| Ottumwa to Ohrdruf | 4,587.66 mi (7,383.13 km) |
| Ottumwa to Ohringen | 4,610.82 mi (7,420.39 km) |
| Ottumwa to Olbernhau | 4,684.62 mi (7,539.16 km) |
| Ottumwa to Olching | 4,718.58 mi (7,593.81 km) |
| Ottumwa to Oldenburg | 4,407.52 mi (7,093.22 km) |
| Ottumwa to Oldenburg in Holstein | 4,451.37 mi (7,163.79 km) |
| Ottumwa to Olfen | 4,434.16 mi (7,136.09 km) |
| Ottumwa to Olpe | 4,477.60 mi (7,206.00 km) |
| Ottumwa to Olsberg | 4,487.45 mi (7,221.86 km) |
| Ottumwa to Oranienburg | 4,592.61 mi (7,391.10 km) |
| Ottumwa to Ortenberg | 4,547.65 mi (7,318.73 km) |
