| Duluth to Oerlinghausen | 4,169.17 mi (6,709.63 km) |
| Duluth to Oestrich-Winkel | 4,233.26 mi (6,812.77 km) |
| Duluth to Offenburg | 4,299.13 mi (6,918.78 km) |
| Duluth to Oftersheim | 4,281.25 mi (6,890.00 km) |
| Duluth to Ohrdruf | 4,287.96 mi (6,900.81 km) |
| Duluth to Ohringen | 4,320.24 mi (6,952.75 km) |
| Duluth to Olbernhau | 4,380.30 mi (7,049.41 km) |
| Duluth to Olching | 4,428.06 mi (7,126.27 km) |
| Duluth to Oldenburg | 4,103.31 mi (6,603.64 km) |
| Duluth to Oldenburg in Holstein | 4,137.85 mi (6,659.23 km) |
| Duluth to Olfen | 4,137.43 mi (6,658.56 km) |
| Duluth to Olpe | 4,182.93 mi (6,731.78 km) |
| Duluth to Olsberg | 4,190.11 mi (6,743.33 km) |
| Duluth to Oranienburg | 4,280.72 mi (6,889.15 km) |
| Duluth to Ortenberg | 4,253.26 mi (6,844.96 km) |
