| Niederkassel to Novi di Modena | 446.66 mi (718.83 km) |
| Niederkassel to Novi Ligure | 426.33 mi (686.11 km) |
| Niederkassel to Nuoro | 733.86 mi (1,181.04 km) |
| Niederkassel to Occhiobello | 458.41 mi (737.74 km) |
| Niederkassel to Oderzo | 428.74 mi (689.99 km) |
| Niederkassel to Oggiono | 363.66 mi (585.26 km) |
| Niederkassel to Olbia | 694.14 mi (1,117.10 km) |
| Niederkassel to Oleggio | 367.87 mi (592.02 km) |
| Niederkassel to Olgiate Comasco | 358.91 mi (577.62 km) |
| Niederkassel to Olgiate Olona | 368.09 mi (592.38 km) |
| Niederkassel to Omegna | 346.99 mi (558.42 km) |
| Niederkassel to Opera | 388.65 mi (625.47 km) |
| Niederkassel to Oppeano | 426.47 mi (686.33 km) |
| Niederkassel to Orbassano | 402.06 mi (647.06 km) |
| Niederkassel to Orbetello | 611.58 mi (984.25 km) |
