| Portimao to Noventa Vicentina | 1,180.83 mi (1,900.37 km) |
| Portimao to Novi di Modena | 1,142.31 mi (1,838.37 km) |
| Portimao to Novi Ligure | 1,043.12 mi (1,678.73 km) |
| Portimao to Nuoro | 986.20 mi (1,587.14 km) |
| Portimao to Occhiobello | 1,174.13 mi (1,889.58 km) |
| Portimao to Oderzo | 1,236.62 mi (1,990.15 km) |
| Portimao to Oggiono | 1,098.33 mi (1,767.59 km) |
| Portimao to Olbia | 1,000.77 mi (1,610.58 km) |
| Portimao to Oleggio | 1,061.76 mi (1,708.73 km) |
| Portimao to Olgiate Comasco | 1,081.87 mi (1,741.10 km) |
| Portimao to Olgiate Olona | 1,073.56 mi (1,727.72 km) |
| Portimao to Omegna | 1,061.15 mi (1,707.75 km) |
| Portimao to Opera | 1,080.38 mi (1,738.70 km) |
| Portimao to Oppeano | 1,165.45 mi (1,875.62 km) |
| Portimao to Orbassano | 995.60 mi (1,602.26 km) |
