| Thornton to Orbetello | 985.72 mi (1,586.36 km) |
| Thornton to Oria | 1,288.51 mi (2,073.65 km) |
| Thornton to Oristano | 1,076.15 mi (1,731.89 km) |
| Thornton to Orta Nova | 1,181.73 mi (1,901.82 km) |
| Thornton to Orte | 1,017.83 mi (1,638.04 km) |
| Thornton to Ortona | 1,084.78 mi (1,745.78 km) |
| Thornton to Orvieto | 995.19 mi (1,601.60 km) |
| Thornton to Orzinuovi | 781.92 mi (1,258.39 km) |
| Thornton to Osimo | 994.58 mi (1,600.61 km) |
| Thornton to Ospitaletto | 777.71 mi (1,251.61 km) |
| Thornton to Ostuni | 1,274.22 mi (2,050.66 km) |
| Thornton to Ottaviano | 1,170.81 mi (1,884.23 km) |
| Thornton to Ovada | 788.30 mi (1,268.65 km) |
| Thornton to Ozieri | 1,042.38 mi (1,677.55 km) |
| Thornton to Paceco | 1,287.75 mi (2,072.43 km) |
