| Boston to Orbetello | 893.63 mi (1,438.15 km) |
| Boston to Oria | 1,194.42 mi (1,922.24 km) |
| Boston to Oristano | 990.01 mi (1,593.27 km) |
| Boston to Orta Nova | 1,087.81 mi (1,750.66 km) |
| Boston to Orte | 924.83 mi (1,488.38 km) |
| Boston to Ortona | 990.92 mi (1,594.74 km) |
| Boston to Orvieto | 902.21 mi (1,451.96 km) |
| Boston to Orzinuovi | 688.60 mi (1,108.20 km) |
| Boston to Osimo | 900.64 mi (1,449.45 km) |
| Boston to Ospitaletto | 684.20 mi (1,101.12 km) |
| Boston to Ostuni | 1,180.12 mi (1,899.22 km) |
| Boston to Ottaviano | 1,077.47 mi (1,734.02 km) |
| Boston to Ovada | 696.92 mi (1,121.58 km) |
| Boston to Ozieri | 954.85 mi (1,536.69 km) |
| Boston to Paceco | 1,197.60 mi (1,927.35 km) |
