| Flensburg to Obernburg am Main | 341.68 mi (549.88 km) |
| Flensburg to Obernkirchen | 174.30 mi (280.50 km) |
| Flensburg to Oberschleissheim | 460.45 mi (741.03 km) |
| Flensburg to Oberstdorf | 510.67 mi (821.84 km) |
| Flensburg to Obertraubling | 418.31 mi (673.20 km) |
| Flensburg to Obertshausen | 326.78 mi (525.89 km) |
| Flensburg to Oberursel | 318.40 mi (512.42 km) |
| Flensburg to Ochsenfurt | 355.58 mi (572.25 km) |
| Flensburg to Ochsenhausen | 464.12 mi (746.92 km) |
| Flensburg to Ochtrup | 200.50 mi (322.68 km) |
| Flensburg to Odenthal | 276.42 mi (444.85 km) |
| Flensburg to Oelde | 210.53 mi (338.82 km) |
| Flensburg to Oelsnitz | 322.57 mi (519.13 km) |
| Flensburg to Oer-Erkenschwick | 235.00 mi (378.20 km) |
| Flensburg to Oerlinghausen | 197.08 mi (317.17 km) |
