| Rio Maior to Nuth | 1,074.07 mi (1,728.55 km) |
| Rio Maior to Oegstgeest | 1,094.19 mi (1,760.93 km) |
| Rio Maior to Oirschot | 1,083.80 mi (1,744.20 km) |
| Rio Maior to Oisterwijk | 1,084.89 mi (1,745.97 km) |
| Rio Maior to Oldebroek | 1,148.64 mi (1,848.56 km) |
| Rio Maior to Oldenzaal | 1,173.01 mi (1,887.78 km) |
| Rio Maior to Ommen | 1,167.12 mi (1,878.30 km) |
| Rio Maior to Oosterend | 1,181.23 mi (1,901.01 km) |
| Rio Maior to Oosterhout | 1,077.69 mi (1,734.38 km) |
| Rio Maior to Oosterwolde | 1,186.96 mi (1,910.23 km) |
| Rio Maior to Oostzaan | 1,118.78 mi (1,800.50 km) |
| Rio Maior to Opmeer | 1,134.48 mi (1,825.77 km) |
| Rio Maior to Oss | 1,103.44 mi (1,775.82 km) |
| Rio Maior to Oud-Beijerland | 1,073.32 mi (1,727.34 km) |
| Rio Maior to Oudenbosch | 1,065.23 mi (1,714.33 km) |
