| Castelfidardo to Oerlinghausen | 629.37 mi (1,012.88 km) |
| Castelfidardo to Oestrich-Winkel | 522.06 mi (840.18 km) |
| Castelfidardo to Offenburg | 438.07 mi (705.01 km) |
| Castelfidardo to Oftersheim | 471.34 mi (758.54 km) |
| Castelfidardo to Ohrdruf | 525.59 mi (845.85 km) |
| Castelfidardo to Ohringen | 440.65 mi (709.16 km) |
| Castelfidardo to Olbernhau | 497.74 mi (801.04 km) |
| Castelfidardo to Olching | 344.32 mi (554.14 km) |
| Castelfidardo to Oldenburg | 711.79 mi (1,145.52 km) |
| Castelfidardo to Oldenburg in Holstein | 758.25 mi (1,220.29 km) |
| Castelfidardo to Olfen | 637.88 mi (1,026.57 km) |
| Castelfidardo to Olpe | 586.19 mi (943.38 km) |
| Castelfidardo to Olsberg | 593.71 mi (955.49 km) |
| Castelfidardo to Oranienburg | 642.05 mi (1,033.28 km) |
| Castelfidardo to Ortenberg | 520.97 mi (838.42 km) |
