| Didcot to Noventa Vicentina | 728.81 mi (1,172.90 km) |
| Didcot to Novi di Modena | 724.45 mi (1,165.89 km) |
| Didcot to Novi Ligure | 660.04 mi (1,062.22 km) |
| Didcot to Nuoro | 928.69 mi (1,494.58 km) |
| Didcot to Occhiobello | 747.28 mi (1,202.64 km) |
| Didcot to Oderzo | 742.71 mi (1,195.27 km) |
| Didcot to Oggiono | 627.54 mi (1,009.92 km) |
| Didcot to Olbia | 897.25 mi (1,443.98 km) |
| Didcot to Oleggio | 612.01 mi (984.93 km) |
| Didcot to Olgiate Comasco | 614.28 mi (988.59 km) |
| Didcot to Olgiate Olona | 618.77 mi (995.82 km) |
| Didcot to Omegna | 590.61 mi (950.50 km) |
| Didcot to Opera | 642.41 mi (1,033.85 km) |
| Didcot to Oppeano | 715.33 mi (1,151.22 km) |
| Didcot to Orbassano | 607.92 mi (978.35 km) |
