| Duluth to Oberkirch | 4,301.38 mi (6,922.40 km) |
| Duluth to Obernburg am Main | 4,279.22 mi (6,886.74 km) |
| Duluth to Obernkirchen | 4,170.85 mi (6,712.33 km) |
| Duluth to Oberschleissheim | 4,434.25 mi (7,136.23 km) |
| Duluth to Oberstdorf | 4,428.94 mi (7,127.68 km) |
| Duluth to Obertraubling | 4,421.17 mi (7,115.19 km) |
| Duluth to Obertshausen | 4,258.64 mi (6,853.63 km) |
| Duluth to Oberursel | 4,243.88 mi (6,829.86 km) |
| Duluth to Ochsenfurt | 4,319.09 mi (6,950.91 km) |
| Duluth to Ochsenhausen | 4,386.97 mi (7,060.15 km) |
| Duluth to Ochtrup | 4,109.98 mi (6,614.37 km) |
| Duluth to Odenthal | 4,158.02 mi (6,691.68 km) |
| Duluth to Oelde | 4,157.91 mi (6,691.51 km) |
| Duluth to Oelsnitz | 4,353.91 mi (7,006.94 km) |
| Duluth to Oer-Erkenschwick | 4,136.22 mi (6,656.60 km) |
