| Alpena to Oerlinghausen | 3,952.28 mi (6,360.58 km) |
| Alpena to Oestrich-Winkel | 4,002.53 mi (6,441.44 km) |
| Alpena to Offenburg | 4,059.21 mi (6,532.66 km) |
| Alpena to Oftersheim | 4,048.48 mi (6,515.39 km) |
| Alpena to Ohrdruf | 4,070.05 mi (6,550.11 km) |
| Alpena to Ohringen | 4,089.15 mi (6,580.85 km) |
| Alpena to Olbernhau | 4,169.14 mi (6,709.59 km) |
| Alpena to Olching | 4,196.71 mi (6,753.95 km) |
| Alpena to Oldenburg | 3,892.59 mi (6,264.51 km) |
| Alpena to Oldenburg in Holstein | 3,941.79 mi (6,343.69 km) |
| Alpena to Olfen | 3,915.44 mi (6,301.29 km) |
| Alpena to Olpe | 3,957.87 mi (6,369.57 km) |
| Alpena to Olsberg | 3,968.91 mi (6,387.34 km) |
| Alpena to Oranienburg | 4,081.66 mi (6,568.80 km) |
| Alpena to Ortenberg | 4,027.67 mi (6,481.91 km) |
