| Caldas da Rainha to Orbetello | 1,080.00 mi (1,738.10 km) |
| Caldas da Rainha to Oria | 1,414.38 mi (2,276.23 km) |
| Caldas da Rainha to Oristano | 942.07 mi (1,516.11 km) |
| Caldas da Rainha to Orta Nova | 1,310.21 mi (2,108.58 km) |
| Caldas da Rainha to Orte | 1,139.80 mi (1,834.32 km) |
| Caldas da Rainha to Ortona | 1,242.12 mi (1,999.00 km) |
| Caldas da Rainha to Orvieto | 1,127.03 mi (1,813.78 km) |
| Caldas da Rainha to Orzinuovi | 1,054.02 mi (1,696.28 km) |
| Caldas da Rainha to Osimo | 1,200.79 mi (1,932.48 km) |
| Caldas da Rainha to Ospitaletto | 1,063.58 mi (1,711.66 km) |
| Caldas da Rainha to Ostuni | 1,410.26 mi (2,269.60 km) |
| Caldas da Rainha to Ottaviano | 1,247.65 mi (2,007.89 km) |
| Caldas da Rainha to Ovada | 979.15 mi (1,575.79 km) |
| Caldas da Rainha to Ozieri | 961.86 mi (1,547.97 km) |
| Caldas da Rainha to Paceco | 1,170.73 mi (1,884.11 km) |
