| Barreiro to Nuth | 1,115.40 mi (1,795.06 km) |
| Barreiro to Oegstgeest | 1,137.39 mi (1,830.45 km) |
| Barreiro to Oirschot | 1,126.01 mi (1,812.14 km) |
| Barreiro to Oisterwijk | 1,127.23 mi (1,814.11 km) |
| Barreiro to Oldebroek | 1,191.31 mi (1,917.23 km) |
| Barreiro to Oldenzaal | 1,215.06 mi (1,955.45 km) |
| Barreiro to Ommen | 1,209.59 mi (1,946.65 km) |
| Barreiro to Oosterend | 1,224.24 mi (1,970.22 km) |
| Barreiro to Oosterhout | 1,120.27 mi (1,802.90 km) |
| Barreiro to Oosterwolde | 1,229.85 mi (1,979.26 km) |
| Barreiro to Oostzaan | 1,161.95 mi (1,869.98 km) |
| Barreiro to Opmeer | 1,177.80 mi (1,895.49 km) |
| Barreiro to Oss | 1,145.76 mi (1,843.93 km) |
| Barreiro to Oud-Beijerland | 1,116.28 mi (1,796.48 km) |
| Barreiro to Oudenbosch | 1,107.95 mi (1,783.08 km) |
