| Dorchester to Orbetello | 861.95 mi (1,387.18 km) |
| Dorchester to Oria | 1,193.32 mi (1,920.47 km) |
| Dorchester to Oristano | 917.09 mi (1,475.92 km) |
| Dorchester to Orta Nova | 1,080.77 mi (1,739.33 km) |
| Dorchester to Orte | 903.06 mi (1,453.34 km) |
| Dorchester to Ortona | 983.44 mi (1,582.70 km) |
| Dorchester to Orvieto | 880.59 mi (1,417.17 km) |
| Dorchester to Orzinuovi | 677.79 mi (1,090.81 km) |
| Dorchester to Osimo | 897.27 mi (1,444.01 km) |
| Dorchester to Ospitaletto | 676.81 mi (1,089.22 km) |
| Dorchester to Ostuni | 1,180.46 mi (1,899.77 km) |
| Dorchester to Ottaviano | 1,058.07 mi (1,702.80 km) |
| Dorchester to Ovada | 663.69 mi (1,068.11 km) |
| Dorchester to Ozieri | 889.61 mi (1,431.69 km) |
| Dorchester to Paceco | 1,145.37 mi (1,843.30 km) |
