| Mechernich to Oestrich-Winkel | 72.58 mi (116.81 km) |
| Mechernich to Offenburg | 158.23 mi (254.64 km) |
| Mechernich to Oftersheim | 120.83 mi (194.46 km) |
| Mechernich to Ohrdruf | 179.29 mi (288.54 km) |
| Mechernich to Ohringen | 159.49 mi (256.68 km) |
| Mechernich to Olbernhau | 292.83 mi (471.26 km) |
| Mechernich to Olching | 267.36 mi (430.27 km) |
| Mechernich to Oldenburg | 187.99 mi (302.54 km) |
| Mechernich to Oldenburg in Holstein | 311.54 mi (501.37 km) |
| Mechernich to Olfen | 83.44 mi (134.29 km) |
| Mechernich to Olpe | 59.14 mi (95.18 km) |
| Mechernich to Olsberg | 95.11 mi (153.06 km) |
| Mechernich to Oranienburg | 318.89 mi (513.21 km) |
| Mechernich to Ortenberg | 107.09 mi (172.35 km) |
| Mechernich to Oschatz | 285.11 mi (458.84 km) |
