| Guadarrama to Noventa Vicentina | 849.76 mi (1,367.55 km) |
| Guadarrama to Novi di Modena | 812.64 mi (1,307.82 km) |
| Guadarrama to Novi Ligure | 710.91 mi (1,144.10 km) |
| Guadarrama to Nuoro | 704.99 mi (1,134.57 km) |
| Guadarrama to Occhiobello | 845.26 mi (1,360.32 km) |
| Guadarrama to Oderzo | 904.14 mi (1,455.08 km) |
| Guadarrama to Oggiono | 761.79 mi (1,225.98 km) |
| Guadarrama to Olbia | 710.29 mi (1,143.09 km) |
| Guadarrama to Oleggio | 725.01 mi (1,166.79 km) |
| Guadarrama to Olgiate Comasco | 744.82 mi (1,198.67 km) |
| Guadarrama to Olgiate Olona | 737.01 mi (1,186.11 km) |
| Guadarrama to Omegna | 723.01 mi (1,163.58 km) |
| Guadarrama to Opera | 745.46 mi (1,199.70 km) |
| Guadarrama to Oppeano | 833.81 mi (1,341.88 km) |
| Guadarrama to Orbassano | 659.90 mi (1,062.00 km) |
