| Herndon to Oberkirch | 4,090.84 mi (6,583.57 km) |
| Herndon to Obernburg am Main | 4,095.09 mi (6,590.41 km) |
| Herndon to Obernkirchen | 4,023.84 mi (6,475.75 km) |
| Herndon to Oberschleissheim | 4,242.47 mi (6,827.59 km) |
| Herndon to Oberstdorf | 4,216.36 mi (6,785.58 km) |
| Herndon to Obertraubling | 4,243.75 mi (6,829.66 km) |
| Herndon to Obertshausen | 4,076.01 mi (6,559.70 km) |
| Herndon to Oberursel | 4,061.73 mi (6,536.72 km) |
| Herndon to Ochsenfurt | 4,138.00 mi (6,659.46 km) |
| Herndon to Ochsenhausen | 4,181.80 mi (6,729.96 km) |
| Herndon to Ochtrup | 3,950.74 mi (6,358.10 km) |
| Herndon to Odenthal | 3,979.81 mi (6,404.88 km) |
| Herndon to Oelde | 3,998.40 mi (6,434.80 km) |
| Herndon to Oelsnitz | 4,197.68 mi (6,755.51 km) |
| Herndon to Oer-Erkenschwick | 3,968.39 mi (6,386.51 km) |
