| Glenn Dale to Oberkirch | 4,066.16 mi (6,543.85 km) |
| Glenn Dale to Obernburg am Main | 4,071.00 mi (6,551.64 km) |
| Glenn Dale to Obernkirchen | 4,000.68 mi (6,438.47 km) |
| Glenn Dale to Oberschleissheim | 4,218.10 mi (6,788.37 km) |
| Glenn Dale to Oberstdorf | 4,191.54 mi (6,745.64 km) |
| Glenn Dale to Obertraubling | 4,219.70 mi (6,790.95 km) |
| Glenn Dale to Obertshausen | 4,051.97 mi (6,521.02 km) |
| Glenn Dale to Oberursel | 4,037.71 mi (6,498.07 km) |
| Glenn Dale to Ochsenfurt | 4,113.94 mi (6,620.75 km) |
| Glenn Dale to Ochsenhausen | 4,157.17 mi (6,690.33 km) |
| Glenn Dale to Ochtrup | 3,927.35 mi (6,320.46 km) |
| Glenn Dale to Odenthal | 3,955.95 mi (6,366.49 km) |
| Glenn Dale to Oelde | 3,974.96 mi (6,397.08 km) |
| Glenn Dale to Oelsnitz | 4,174.16 mi (6,717.65 km) |
| Glenn Dale to Oer-Erkenschwick | 3,944.78 mi (6,348.51 km) |
