| Castelli Calepio to Oria | 526.97 mi (848.07 km) |
| Castelli Calepio to Oristano | 401.24 mi (645.74 km) |
| Castelli Calepio to Orta Nova | 416.02 mi (669.52 km) |
| Castelli Calepio to Orte | 251.58 mi (404.87 km) |
| Castelli Calepio to Ortona | 318.49 mi (512.56 km) |
| Castelli Calepio to Orvieto | 229.24 mi (368.93 km) |
| Castelli Calepio to Orzinuovi | 16.20 mi (26.07 km) |
| Castelli Calepio to Osimo | 230.58 mi (371.09 km) |
| Castelli Calepio to Ospitaletto | 9.96 mi (16.03 km) |
| Castelli Calepio to Ostuni | 513.83 mi (826.93 km) |
| Castelli Calepio to Ottaviano | 402.72 mi (648.11 km) |
| Castelli Calepio to Ovada | 91.93 mi (147.94 km) |
| Castelli Calepio to Ozieri | 351.72 mi (566.05 km) |
| Castelli Calepio to Paceco | 545.81 mi (878.40 km) |
| Castelli Calepio to Pachino | 672.44 mi (1,082.19 km) |
