| Oak Forest to Oberkirch | 4,382.93 mi (7,053.65 km) |
| Oak Forest to Obernburg am Main | 4,372.48 mi (7,036.83 km) |
| Oak Forest to Obernkirchen | 4,279.67 mi (6,887.46 km) |
| Oak Forest to Oberschleissheim | 4,525.36 mi (7,282.87 km) |
| Oak Forest to Oberstdorf | 4,510.62 mi (7,259.13 km) |
| Oak Forest to Obertraubling | 4,518.62 mi (7,272.01 km) |
| Oak Forest to Obertshausen | 4,352.40 mi (7,004.51 km) |
| Oak Forest to Oberursel | 4,337.73 mi (6,980.89 km) |
| Oak Forest to Ochsenfurt | 4,414.05 mi (7,103.73 km) |
| Oak Forest to Ochsenhausen | 4,471.67 mi (7,196.45 km) |
| Oak Forest to Ochtrup | 4,212.85 mi (6,779.93 km) |
| Oak Forest to Odenthal | 4,252.88 mi (6,844.35 km) |
| Oak Forest to Oelde | 4,261.09 mi (6,857.56 km) |
| Oak Forest to Oelsnitz | 4,460.22 mi (7,178.04 km) |
| Oak Forest to Oer-Erkenschwick | 4,235.51 mi (6,816.40 km) |
