| Southborough to Orbetello | 792.73 mi (1,275.77 km) |
| Southborough to Oria | 1,109.25 mi (1,785.16 km) |
| Southborough to Oristano | 874.49 mi (1,407.36 km) |
| Southborough to Orta Nova | 999.25 mi (1,608.14 km) |
| Southborough to Orte | 828.49 mi (1,333.33 km) |
| Southborough to Ortona | 901.74 mi (1,451.20 km) |
| Southborough to Orvieto | 805.81 mi (1,296.83 km) |
| Southborough to Orzinuovi | 595.77 mi (958.80 km) |
| Southborough to Osimo | 813.07 mi (1,308.51 km) |
| Southborough to Ospitaletto | 593.02 mi (954.37 km) |
| Southborough to Ostuni | 1,095.65 mi (1,763.27 km) |
| Southborough to Ottaviano | 982.91 mi (1,581.84 km) |
| Southborough to Ovada | 593.97 mi (955.90 km) |
| Southborough to Ozieri | 841.59 mi (1,354.41 km) |
| Southborough to Paceco | 1,089.70 mi (1,753.70 km) |
