| Santiago do Cacem to Orbetello | 1,091.04 mi (1,755.85 km) |
| Santiago do Cacem to Oria | 1,413.90 mi (2,275.45 km) |
| Santiago do Cacem to Oristano | 936.60 mi (1,507.32 km) |
| Santiago do Cacem to Orta Nova | 1,313.72 mi (2,114.23 km) |
| Santiago do Cacem to Orte | 1,150.36 mi (1,851.32 km) |
| Santiago do Cacem to Ortona | 1,251.32 mi (2,013.81 km) |
| Santiago do Cacem to Orvieto | 1,139.28 mi (1,833.50 km) |
| Santiago do Cacem to Orzinuovi | 1,084.46 mi (1,745.27 km) |
| Santiago do Cacem to Osimo | 1,216.70 mi (1,958.09 km) |
| Santiago do Cacem to Ospitaletto | 1,094.72 mi (1,761.78 km) |
| Santiago do Cacem to Ostuni | 1,410.92 mi (2,270.65 km) |
| Santiago do Cacem to Ottaviano | 1,248.50 mi (2,009.26 km) |
| Santiago do Cacem to Ovada | 1,006.83 mi (1,620.33 km) |
| Santiago do Cacem to Ozieri | 961.30 mi (1,547.06 km) |
| Santiago do Cacem to Paceco | 1,154.45 mi (1,857.91 km) |
