| Ostend to Oestrich-Winkel | 238.25 mi (383.42 km) |
| Ostend to Offenburg | 293.56 mi (472.44 km) |
| Ostend to Oftersheim | 280.88 mi (452.03 km) |
| Ostend to Ohrdruf | 340.49 mi (547.97 km) |
| Ostend to Ohringen | 322.72 mi (519.37 km) |
| Ostend to Olbernhau | 454.60 mi (731.60 km) |
| Ostend to Olching | 429.12 mi (690.60 km) |
| Ostend to Oldenburg | 260.42 mi (419.10 km) |
| Ostend to Oldenburg in Holstein | 394.59 mi (635.04 km) |
| Ostend to Olfen | 195.06 mi (313.92 km) |
| Ostend to Olpe | 213.56 mi (343.68 km) |
| Ostend to Olsberg | 240.52 mi (387.08 km) |
| Ostend to Oranienburg | 451.08 mi (725.94 km) |
| Ostend to Ortenberg | 274.57 mi (441.88 km) |
| Ostend to Oschatz | 440.14 mi (708.34 km) |
