| Trets to Obernburg am Main | 471.02 mi (758.03 km) |
| Trets to Obernkirchen | 629.61 mi (1,013.26 km) |
| Trets to Oberschleissheim | 435.90 mi (701.51 km) |
| Trets to Oberstdorf | 352.82 mi (567.81 km) |
| Trets to Obertraubling | 490.99 mi (790.18 km) |
| Trets to Obertshausen | 480.92 mi (773.97 km) |
| Trets to Oberursel | 486.32 mi (782.65 km) |
| Trets to Ochsenfurt | 476.27 mi (766.48 km) |
| Trets to Ochsenhausen | 379.79 mi (611.21 km) |
| Trets to Ochtrup | 609.14 mi (980.32 km) |
| Trets to Odenthal | 528.42 mi (850.41 km) |
| Trets to Oelde | 590.60 mi (950.48 km) |
| Trets to Oelsnitz | 569.95 mi (917.25 km) |
| Trets to Oer-Erkenschwick | 570.89 mi (918.76 km) |
| Trets to Oerlinghausen | 604.62 mi (973.04 km) |
