| Hamm to Navodari | 1,082.37 mi (1,741.90 km) |
| Hamm to Negresti-Oas | 742.77 mi (1,195.38 km) |
| Hamm to Nehoiu | 948.81 mi (1,526.95 km) |
| Hamm to Ocna Mures | 811.18 mi (1,305.46 km) |
| Hamm to Odobesti | 964.10 mi (1,551.57 km) |
| Hamm to Odorheiu Secuiesc | 872.23 mi (1,403.72 km) |
| Hamm to Oltenita | 1,013.39 mi (1,630.89 km) |
| Hamm to Onesti | 934.25 mi (1,503.53 km) |
| Hamm to Oradea | 708.37 mi (1,140.02 km) |
| Hamm to Orastie | 805.92 mi (1,297.00 km) |
| Hamm to Oravita | 782.77 mi (1,259.75 km) |
| Hamm to Orsova | 823.33 mi (1,325.02 km) |
| Hamm to Otelu Rosu | 786.86 mi (1,266.33 km) |
| Hamm to Otopeni | 971.69 mi (1,563.79 km) |
| Hamm to Ovidiu | 1,082.27 mi (1,741.74 km) |
