| Flensburg to Opwijk | 342.57 mi (551.31 km) |
| Flensburg to Ostend | 365.51 mi (588.23 km) |
| Flensburg to Oud-Heverlee | 337.65 mi (543.40 km) |
| Flensburg to Oud-Turnhout | 302.42 mi (486.70 km) |
| Flensburg to Oudenaarde | 364.73 mi (586.98 km) |
| Flensburg to Oudenburg | 365.13 mi (587.62 km) |
| Flensburg to Oupeye | 322.99 mi (519.81 km) |
| Flensburg to Overijse | 343.80 mi (553.29 km) |
| Flensburg to Overpelt | 297.59 mi (478.92 km) |
| Flensburg to Paal | 313.62 mi (504.72 km) |
| Flensburg to Peer | 301.64 mi (485.45 km) |
| Flensburg to Pepinster | 328.26 mi (528.28 km) |
| Flensburg to Peruwelz | 383.20 mi (616.71 km) |
| Flensburg to Perwez | 346.20 mi (557.15 km) |
| Flensburg to Philippeville | 377.27 mi (607.16 km) |
