| Upper Montclair to Oberkirch | 3,878.15 mi (6,241.28 km) |
| Upper Montclair to Obernburg am Main | 3,882.65 mi (6,248.52 km) |
| Upper Montclair to Obernkirchen | 3,812.15 mi (6,135.06 km) |
| Upper Montclair to Oberschleissheim | 4,029.89 mi (6,485.48 km) |
| Upper Montclair to Oberstdorf | 4,003.64 mi (6,443.24 km) |
| Upper Montclair to Obertraubling | 4,031.34 mi (6,487.81 km) |
| Upper Montclair to Obertshausen | 3,863.60 mi (6,217.86 km) |
| Upper Montclair to Oberursel | 3,849.33 mi (6,194.90 km) |
| Upper Montclair to Ochsenfurt | 3,925.58 mi (6,317.61 km) |
| Upper Montclair to Ochsenhausen | 3,969.13 mi (6,387.70 km) |
| Upper Montclair to Ochtrup | 3,738.82 mi (6,017.06 km) |
| Upper Montclair to Odenthal | 3,767.52 mi (6,063.23 km) |
| Upper Montclair to Oelde | 3,786.44 mi (6,093.68 km) |
| Upper Montclair to Oelsnitz | 3,985.65 mi (6,414.28 km) |
| Upper Montclair to Oer-Erkenschwick | 3,756.29 mi (6,045.16 km) |
