| Didcot to Olivares | 1,009.19 mi (1,624.14 km) |
| Didcot to Olivenza | 936.49 mi (1,507.14 km) |
| Didcot to Olot | 674.28 mi (1,085.15 km) |
| Didcot to Onate | 594.85 mi (957.32 km) |
| Didcot to Onda | 805.84 mi (1,296.88 km) |
| Didcot to Onteniente | 883.80 mi (1,422.35 km) |
| Didcot to Orihuela | 934.28 mi (1,503.58 km) |
| Didcot to Osuna | 1,010.78 mi (1,626.70 km) |
| Didcot to Ourense | 711.81 mi (1,145.55 km) |
| Didcot to Oviedo | 608.64 mi (979.51 km) |
| Didcot to Paiporta | 842.36 mi (1,355.65 km) |
| Didcot to Pajara | 1,739.15 mi (2,798.89 km) |
| Didcot to Palafolls | 711.92 mi (1,145.73 km) |
| Didcot to Palafrugell | 700.79 mi (1,127.81 km) |
| Didcot to Palamos | 705.08 mi (1,134.72 km) |
