| The Dalles to Orbetello | 5,686.02 mi (9,150.77 km) |
| The Dalles to Oria | 5,966.08 mi (9,601.47 km) |
| The Dalles to Oristano | 5,761.87 mi (9,272.84 km) |
| The Dalles to Orta Nova | 5,868.19 mi (9,443.94 km) |
| The Dalles to Orte | 5,715.67 mi (9,198.49 km) |
| The Dalles to Ortona | 5,773.83 mi (9,292.09 km) |
| The Dalles to Orvieto | 5,693.18 mi (9,162.28 km) |
| The Dalles to Orzinuovi | 5,478.75 mi (8,817.20 km) |
| The Dalles to Osimo | 5,682.83 mi (9,145.64 km) |
| The Dalles to Ospitaletto | 5,473.33 mi (8,808.47 km) |
| The Dalles to Ostuni | 5,950.57 mi (9,576.51 km) |
| The Dalles to Ottaviano | 5,866.04 mi (9,440.49 km) |
| The Dalles to Ovada | 5,488.91 mi (8,833.55 km) |
| The Dalles to Ozieri | 5,734.10 mi (9,228.14 km) |
| The Dalles to Paceco | 5,986.42 mi (9,634.22 km) |
