| Portimao to Nuth | 1,187.03 mi (1,910.33 km) |
| Portimao to Oegstgeest | 1,216.20 mi (1,957.28 km) |
| Portimao to Oirschot | 1,200.92 mi (1,932.69 km) |
| Portimao to Oisterwijk | 1,202.63 mi (1,935.45 km) |
| Portimao to Oldebroek | 1,267.85 mi (2,040.40 km) |
| Portimao to Oldenzaal | 1,289.09 mi (2,074.58 km) |
| Portimao to Ommen | 1,285.27 mi (2,068.44 km) |
| Portimao to Oosterend | 1,302.02 mi (2,095.39 km) |
| Portimao to Oosterhout | 1,196.63 mi (1,925.78 km) |
| Portimao to Oosterwolde | 1,307.15 mi (2,103.66 km) |
| Portimao to Oostzaan | 1,240.56 mi (1,996.49 km) |
| Portimao to Opmeer | 1,257.01 mi (2,022.96 km) |
| Portimao to Oss | 1,221.04 mi (1,965.07 km) |
| Portimao to Oud-Beijerland | 1,194.19 mi (1,921.86 km) |
| Portimao to Oudenbosch | 1,184.89 mi (1,906.90 km) |
