| Frechen to Oestrich-Winkel | 81.98 mi (131.93 km) |
| Frechen to Offenburg | 176.48 mi (284.01 km) |
| Frechen to Oftersheim | 132.43 mi (213.13 km) |
| Frechen to Ohrdruf | 170.84 mi (274.94 km) |
| Frechen to Ohringen | 168.02 mi (270.39 km) |
| Frechen to Olbernhau | 285.05 mi (458.75 km) |
| Frechen to Olching | 275.43 mi (443.25 km) |
| Frechen to Oldenburg | 164.94 mi (265.45 km) |
| Frechen to Oldenburg in Holstein | 289.31 mi (465.59 km) |
| Frechen to Olfen | 60.45 mi (97.28 km) |
| Frechen to Olpe | 44.77 mi (72.05 km) |
| Frechen to Olsberg | 78.21 mi (125.87 km) |
| Frechen to Oranienburg | 301.94 mi (485.93 km) |
| Frechen to Ortenberg | 105.47 mi (169.74 km) |
| Frechen to Oschatz | 274.08 mi (441.09 km) |
