| Greenford to Olivares | 1,015.40 mi (1,634.12 km) |
| Greenford to Olivenza | 945.55 mi (1,521.72 km) |
| Greenford to Olot | 659.50 mi (1,061.36 km) |
| Greenford to Onate | 594.94 mi (957.46 km) |
| Greenford to Onda | 799.24 mi (1,286.25 km) |
| Greenford to Onteniente | 878.11 mi (1,413.17 km) |
| Greenford to Orihuela | 929.37 mi (1,495.67 km) |
| Greenford to Osuna | 1,014.73 mi (1,633.04 km) |
| Greenford to Ourense | 726.56 mi (1,169.29 km) |
| Greenford to Oviedo | 619.73 mi (997.36 km) |
| Greenford to Paiporta | 836.18 mi (1,345.70 km) |
| Greenford to Pajara | 1,752.70 mi (2,820.70 km) |
| Greenford to Palafolls | 696.85 mi (1,121.47 km) |
| Greenford to Palafrugell | 684.46 mi (1,101.53 km) |
| Greenford to Palamos | 688.90 mi (1,108.68 km) |
