| Castel Bolognese to Novi di Modena | 59.53 mi (95.80 km) |
| Castel Bolognese to Novi Ligure | 151.56 mi (243.91 km) |
| Castel Bolognese to Nuoro | 303.71 mi (488.78 km) |
| Castel Bolognese to Occhiobello | 43.16 mi (69.46 km) |
| Castel Bolognese to Oderzo | 106.66 mi (171.66 km) |
| Castel Bolognese to Oggiono | 156.74 mi (252.24 km) |
| Castel Bolognese to Olbia | 262.39 mi (422.27 km) |
| Castel Bolognese to Oleggio | 178.40 mi (287.10 km) |
| Castel Bolognese to Olgiate Comasco | 171.44 mi (275.90 km) |
| Castel Bolognese to Olgiate Olona | 169.10 mi (272.13 km) |
| Castel Bolognese to Omegna | 197.52 mi (317.88 km) |
| Castel Bolognese to Opera | 146.42 mi (235.65 km) |
| Castel Bolognese to Oppeano | 74.36 mi (119.67 km) |
| Castel Bolognese to Orbassano | 214.84 mi (345.75 km) |
| Castel Bolognese to Orbetello | 133.02 mi (214.08 km) |
