| Gurnee to Oberkirch | 4,354.30 mi (7,007.56 km) |
| Gurnee to Obernburg am Main | 4,342.55 mi (6,988.66 km) |
| Gurnee to Obernkirchen | 4,247.99 mi (6,836.48 km) |
| Gurnee to Oberschleissheim | 4,495.77 mi (7,235.23 km) |
| Gurnee to Oberstdorf | 4,482.05 mi (7,213.16 km) |
| Gurnee to Obertraubling | 4,488.32 mi (7,223.26 km) |
| Gurnee to Obertshausen | 4,322.40 mi (6,956.23 km) |
| Gurnee to Oberursel | 4,307.71 mi (6,932.58 km) |
| Gurnee to Ochsenfurt | 4,383.96 mi (7,055.30 km) |
| Gurnee to Ochsenhausen | 4,442.74 mi (7,149.90 km) |
| Gurnee to Ochtrup | 4,181.77 mi (6,729.91 km) |
| Gurnee to Odenthal | 4,222.69 mi (6,795.77 km) |
| Gurnee to Oelde | 4,230.00 mi (6,807.53 km) |
| Gurnee to Oelsnitz | 4,428.93 mi (7,127.68 km) |
| Gurnee to Oer-Erkenschwick | 4,204.83 mi (6,767.02 km) |
