| Didcot to Orbetello | 860.93 mi (1,385.54 km) |
| Didcot to Oria | 1,180.33 mi (1,899.56 km) |
| Didcot to Oristano | 935.23 mi (1,505.11 km) |
| Didcot to Orta Nova | 1,069.95 mi (1,721.92 km) |
| Didcot to Orte | 897.88 mi (1,444.99 km) |
| Didcot to Ortona | 972.41 mi (1,564.95 km) |
| Didcot to Orvieto | 875.21 mi (1,408.52 km) |
| Didcot to Orzinuovi | 666.22 mi (1,072.18 km) |
| Didcot to Osimo | 884.04 mi (1,422.73 km) |
| Didcot to Ospitaletto | 663.74 mi (1,068.18 km) |
| Didcot to Ostuni | 1,166.82 mi (1,877.81 km) |
| Didcot to Ottaviano | 1,052.54 mi (1,693.89 km) |
| Didcot to Ovada | 661.95 mi (1,065.30 km) |
| Didcot to Ozieri | 904.04 mi (1,454.92 km) |
| Didcot to Paceco | 1,154.78 mi (1,858.43 km) |
