| Alenquer to Orbetello | 1,081.73 mi (1,740.88 km) |
| Alenquer to Oria | 1,413.34 mi (2,274.55 km) |
| Alenquer to Oristano | 939.40 mi (1,511.82 km) |
| Alenquer to Orta Nova | 1,310.15 mi (2,108.48 km) |
| Alenquer to Orte | 1,141.45 mi (1,836.98 km) |
| Alenquer to Ortona | 1,243.49 mi (2,001.20 km) |
| Alenquer to Orvieto | 1,129.11 mi (1,817.13 km) |
| Alenquer to Orzinuovi | 1,060.81 mi (1,707.21 km) |
| Alenquer to Osimo | 1,203.87 mi (1,937.44 km) |
| Alenquer to Ospitaletto | 1,070.56 mi (1,722.91 km) |
| Alenquer to Ostuni | 1,409.51 mi (2,268.39 km) |
| Alenquer to Ottaviano | 1,246.86 mi (2,006.62 km) |
| Alenquer to Ovada | 985.15 mi (1,585.45 km) |
| Alenquer to Ozieri | 960.48 mi (1,545.74 km) |
| Alenquer to Paceco | 1,165.50 mi (1,875.69 km) |
