| Downers Grove to Oberkirch | 4,384.12 mi (7,055.56 km) |
| Downers Grove to Obernburg am Main | 4,373.13 mi (7,037.87 km) |
| Downers Grove to Obernkirchen | 4,279.56 mi (6,887.29 km) |
| Downers Grove to Oberschleissheim | 4,526.15 mi (7,284.14 km) |
| Downers Grove to Oberstdorf | 4,511.83 mi (7,261.09 km) |
| Downers Grove to Obertraubling | 4,519.11 mi (7,272.81 km) |
| Downers Grove to Obertshausen | 4,353.02 mi (7,005.50 km) |
| Downers Grove to Oberursel | 4,338.33 mi (6,981.87 km) |
| Downers Grove to Ochsenfurt | 4,414.63 mi (7,104.66 km) |
| Downers Grove to Ochsenhausen | 4,472.73 mi (7,198.17 km) |
| Downers Grove to Ochtrup | 4,213.00 mi (6,780.17 km) |
| Downers Grove to Odenthal | 4,253.41 mi (6,845.21 km) |
| Downers Grove to Oelde | 4,261.24 mi (6,857.80 km) |
| Downers Grove to Oelsnitz | 4,460.29 mi (7,178.14 km) |
| Downers Grove to Oer-Erkenschwick | 4,235.84 mi (6,816.92 km) |
