| Oud-Heverlee to Navodari | 1,196.73 mi (1,925.96 km) |
| Oud-Heverlee to Negresti-Oas | 866.15 mi (1,393.94 km) |
| Oud-Heverlee to Nehoiu | 1,063.19 mi (1,711.03 km) |
| Oud-Heverlee to Ocna Mures | 925.78 mi (1,489.90 km) |
| Oud-Heverlee to Odobesti | 1,082.46 mi (1,742.05 km) |
| Oud-Heverlee to Odorheiu Secuiesc | 989.83 mi (1,592.97 km) |
| Oud-Heverlee to Oltenita | 1,121.62 mi (1,805.07 km) |
| Oud-Heverlee to Onesti | 1,054.63 mi (1,697.26 km) |
| Oud-Heverlee to Oradea | 822.61 mi (1,323.86 km) |
| Oud-Heverlee to Orastie | 915.03 mi (1,472.61 km) |
| Oud-Heverlee to Oravita | 880.80 mi (1,417.50 km) |
| Oud-Heverlee to Orsova | 921.83 mi (1,483.54 km) |
| Oud-Heverlee to Otelu Rosu | 890.89 mi (1,433.74 km) |
| Oud-Heverlee to Otopeni | 1,080.94 mi (1,739.61 km) |
| Oud-Heverlee to Ovidiu | 1,196.27 mi (1,925.21 km) |
