| Guadarrama to Oerlinghausen | 986.63 mi (1,587.83 km) |
| Guadarrama to Oestrich-Winkel | 869.65 mi (1,399.57 km) |
| Guadarrama to Offenburg | 798.38 mi (1,284.87 km) |
| Guadarrama to Oftersheim | 860.54 mi (1,384.90 km) |
| Guadarrama to Ohrdruf | 997.96 mi (1,606.07 km) |
| Guadarrama to Ohringen | 885.77 mi (1,425.50 km) |
| Guadarrama to Olbernhau | 1,083.58 mi (1,743.85 km) |
| Guadarrama to Olching | 918.25 mi (1,477.78 km) |
| Guadarrama to Oldenburg | 1,035.91 mi (1,667.13 km) |
| Guadarrama to Oldenburg in Holstein | 1,167.53 mi (1,878.96 km) |
| Guadarrama to Olfen | 937.45 mi (1,508.67 km) |
| Guadarrama to Olpe | 914.17 mi (1,471.21 km) |
| Guadarrama to Olsberg | 950.26 mi (1,529.29 km) |
| Guadarrama to Oranienburg | 1,164.83 mi (1,874.61 km) |
| Guadarrama to Ortenberg | 920.72 mi (1,481.75 km) |
