| Estarreja to Orbetello | 1,026.32 mi (1,651.70 km) |
| Estarreja to Oria | 1,368.93 mi (2,203.08 km) |
| Estarreja to Oristano | 904.22 mi (1,455.21 km) |
| Estarreja to Orta Nova | 1,261.72 mi (2,030.54 km) |
| Estarreja to Orte | 1,086.13 mi (1,747.96 km) |
| Estarreja to Ortona | 1,189.05 mi (1,913.60 km) |
| Estarreja to Orvieto | 1,072.02 mi (1,725.24 km) |
| Estarreja to Orzinuovi | 984.75 mi (1,584.80 km) |
| Estarreja to Osimo | 1,142.30 mi (1,838.35 km) |
| Estarreja to Ospitaletto | 993.72 mi (1,599.24 km) |
| Estarreja to Ostuni | 1,363.82 mi (2,194.85 km) |
| Estarreja to Ottaviano | 1,201.81 mi (1,934.12 km) |
| Estarreja to Ovada | 912.47 mi (1,468.47 km) |
| Estarreja to Ozieri | 919.33 mi (1,479.52 km) |
| Estarreja to Paceco | 1,141.18 mi (1,836.55 km) |
