| Gengenbach to Oestrich-Winkel | 110.55 mi (177.92 km) |
| Gengenbach to Offenburg | 5.99 mi (9.64 km) |
| Gengenbach to Oftersheim | 71.86 mi (115.64 km) |
| Gengenbach to Ohrdruf | 207.16 mi (333.40 km) |
| Gengenbach to Ohringen | 87.25 mi (140.41 km) |
| Gengenbach to Olbernhau | 285.14 mi (458.89 km) |
| Gengenbach to Olching | 152.29 mi (245.09 km) |
| Gengenbach to Oldenburg | 327.88 mi (527.68 km) |
| Gengenbach to Oldenburg in Holstein | 425.91 mi (685.44 km) |
| Gengenbach to Olfen | 230.88 mi (371.56 km) |
| Gengenbach to Olpe | 180.98 mi (291.26 km) |
| Gengenbach to Olsberg | 204.88 mi (329.72 km) |
| Gengenbach to Oranienburg | 377.91 mi (608.20 km) |
| Gengenbach to Ortenberg | 142.98 mi (230.10 km) |
| Gengenbach to Oschatz | 302.51 mi (486.84 km) |
