| Piraeus to Oegstgeest | 1,349.81 mi (2,172.30 km) |
| Piraeus to Oirschot | 1,292.39 mi (2,079.90 km) |
| Piraeus to Oisterwijk | 1,299.36 mi (2,091.12 km) |
| Piraeus to Oldebroek | 1,316.10 mi (2,118.05 km) |
| Piraeus to Oldenzaal | 1,278.13 mi (2,056.95 km) |
| Piraeus to Ommen | 1,303.39 mi (2,097.60 km) |
| Piraeus to Oosterend | 1,337.26 mi (2,152.12 km) |
| Piraeus to Oosterhout | 1,313.40 mi (2,113.71 km) |
| Piraeus to Oosterwolde | 1,329.92 mi (2,140.30 km) |
| Piraeus to Oostzaan | 1,347.38 mi (2,168.39 km) |
| Piraeus to Opmeer | 1,357.32 mi (2,184.40 km) |
| Piraeus to Oss | 1,297.04 mi (2,087.39 km) |
| Piraeus to Oud-Beijerland | 1,336.17 mi (2,150.35 km) |
| Piraeus to Oudenbosch | 1,322.29 mi (2,128.01 km) |
| Piraeus to Oudewater | 1,329.38 mi (2,139.43 km) |
