| Southborough to Olivares | 1,000.21 mi (1,609.68 km) |
| Southborough to Olivenza | 933.03 mi (1,501.56 km) |
| Southborough to Olot | 629.11 mi (1,012.45 km) |
| Southborough to Onate | 575.38 mi (925.98 km) |
| Southborough to Onda | 774.08 mi (1,245.76 km) |
| Southborough to Onteniente | 853.49 mi (1,373.57 km) |
| Southborough to Orihuela | 905.27 mi (1,456.89 km) |
| Southborough to Osuna | 997.57 mi (1,605.44 km) |
| Southborough to Ourense | 719.95 mi (1,158.65 km) |
| Southborough to Oviedo | 609.84 mi (981.44 km) |
| Southborough to Paiporta | 811.27 mi (1,305.62 km) |
| Southborough to Pajara | 1,743.82 mi (2,806.40 km) |
| Southborough to Palafolls | 666.23 mi (1,072.20 km) |
| Southborough to Palafrugell | 653.13 mi (1,051.12 km) |
| Southborough to Palamos | 657.65 mi (1,058.39 km) |
