| Targu Ocna to Nuth | 996.27 mi (1,603.34 km) |
| Targu Ocna to Oegstgeest | 1,074.15 mi (1,728.67 km) |
| Targu Ocna to Oirschot | 1,028.99 mi (1,655.99 km) |
| Targu Ocna to Oisterwijk | 1,034.40 mi (1,664.71 km) |
| Targu Ocna to Oldebroek | 1,020.41 mi (1,642.19 km) |
| Targu Ocna to Oldenzaal | 976.04 mi (1,570.78 km) |
| Targu Ocna to Ommen | 1,000.95 mi (1,610.87 km) |
| Targu Ocna to Oosterend | 1,025.30 mi (1,650.05 km) |
| Targu Ocna to Oosterhout | 1,049.66 mi (1,689.27 km) |
| Targu Ocna to Oosterwolde | 1,016.14 mi (1,635.32 km) |
| Targu Ocna to Oostzaan | 1,061.33 mi (1,708.04 km) |
| Targu Ocna to Opmeer | 1,063.53 mi (1,711.59 km) |
| Targu Ocna to Oss | 1,023.99 mi (1,647.95 km) |
| Targu Ocna to Oud-Beijerland | 1,071.30 mi (1,724.09 km) |
| Targu Ocna to Oudenbosch | 1,062.89 mi (1,710.56 km) |
