| Horndean to Oerlinghausen | 422.14 mi (679.37 km) |
| Horndean to Oestrich-Winkel | 400.47 mi (644.49 km) |
| Horndean to Offenburg | 433.09 mi (697.00 km) |
| Horndean to Oftersheim | 437.09 mi (703.43 km) |
| Horndean to Ohrdruf | 510.91 mi (822.23 km) |
| Horndean to Ohringen | 479.96 mi (772.43 km) |
| Horndean to Olbernhau | 625.13 mi (1,006.05 km) |
| Horndean to Olching | 582.01 mi (936.66 km) |
| Horndean to Oldenburg | 420.38 mi (676.53 km) |
| Horndean to Oldenburg in Holstein | 549.72 mi (884.69 km) |
| Horndean to Olfen | 365.89 mi (588.84 km) |
| Horndean to Olpe | 384.04 mi (618.06 km) |
| Horndean to Olsberg | 411.82 mi (662.77 km) |
| Horndean to Oranienburg | 619.76 mi (997.40 km) |
| Horndean to Ortenberg | 441.82 mi (711.04 km) |
