| Oberhausen to Navodari | 1,116.65 mi (1,797.08 km) |
| Oberhausen to Negresti-Oas | 779.28 mi (1,254.13 km) |
| Oberhausen to Nehoiu | 982.99 mi (1,581.97 km) |
| Oberhausen to Ocna Mures | 845.28 mi (1,360.34 km) |
| Oberhausen to Odobesti | 999.41 mi (1,608.39 km) |
| Oberhausen to Odorheiu Secuiesc | 907.25 mi (1,460.07 km) |
| Oberhausen to Oltenita | 1,045.91 mi (1,683.22 km) |
| Oberhausen to Onesti | 970.09 mi (1,561.22 km) |
| Oberhausen to Oradea | 742.23 mi (1,194.50 km) |
| Oberhausen to Orastie | 838.45 mi (1,349.35 km) |
| Oberhausen to Oravita | 812.06 mi (1,306.89 km) |
| Oberhausen to Orsova | 852.83 mi (1,372.50 km) |
| Oberhausen to Otelu Rosu | 817.90 mi (1,316.28 km) |
| Oberhausen to Otopeni | 1,004.46 mi (1,616.52 km) |
| Oberhausen to Ovidiu | 1,116.45 mi (1,796.76 km) |
