| Didcot to Orangevale (California) | 5,227.62 mi (8,413.04 km) |
| Didcot to Orchards (Washington) | 4,863.96 mi (7,827.79 km) |
| Didcot to Orcutt (California) | 5,422.77 mi (8,727.10 km) |
| Didcot to Oregon (Ohio) | 3,749.80 mi (6,034.72 km) |
| Didcot to Oregon (Wisconsin) | 3,920.21 mi (6,308.97 km) |
| Didcot to Oregon City (Oregon) | 4,885.48 mi (7,862.42 km) |
| Didcot to Orem (Utah) | 4,839.38 mi (7,788.24 km) |
| Didcot to Orinda (California) | 5,302.80 mi (8,534.04 km) |
| Didcot to Orland Park (Illinois) | 3,923.35 mi (6,314.02 km) |
| Didcot to Orlando (Florida) | 4,292.16 mi (6,907.57 km) |
| Didcot to Ormond Beach (Florida) | 4,241.43 mi (6,825.93 km) |
| Didcot to Oro Valley (Arizona) | 5,246.02 mi (8,442.65 km) |
| Didcot to Oroville (California) | 5,191.15 mi (8,354.36 km) |
| Didcot to Oshkosh (Wisconsin) | 3,838.83 mi (6,178.00 km) |
| Didcot to Oskaloosa (Iowa) | 4,119.01 mi (6,628.90 km) |
