| Detroit to Orbetello | 4,529.20 mi (7,289.04 km) |
| Detroit to Oria | 4,873.81 mi (7,843.63 km) |
| Detroit to Oristano | 4,521.25 mi (7,276.25 km) |
| Detroit to Orta Nova | 4,759.73 mi (7,660.05 km) |
| Detroit to Orte | 4,576.59 mi (7,365.30 km) |
| Detroit to Ortona | 4,663.18 mi (7,504.66 km) |
| Detroit to Orvieto | 4,554.71 mi (7,330.10 km) |
| Detroit to Orzinuovi | 4,359.49 mi (7,015.92 km) |
| Detroit to Osimo | 4,578.92 mi (7,369.06 km) |
| Detroit to Ospitaletto | 4,359.07 mi (7,015.24 km) |
| Detroit to Ostuni | 4,861.50 mi (7,823.83 km) |
| Detroit to Ottaviano | 4,729.89 mi (7,612.02 km) |
| Detroit to Ovada | 4,336.82 mi (6,979.43 km) |
| Detroit to Ozieri | 4,511.51 mi (7,260.57 km) |
| Detroit to Paceco | 4,771.06 mi (7,678.28 km) |
