| Sioux City to Nasaud | 5,257.96 mi (8,461.87 km) |
| Sioux City to Navodari | 5,544.57 mi (8,923.12 km) |
| Sioux City to Negresti-Oas | 5,197.34 mi (8,364.32 km) |
| Sioux City to Nehoiu | 5,418.34 mi (8,719.97 km) |
| Sioux City to Ocna Mures | 5,287.78 mi (8,509.85 km) |
| Sioux City to Odobesti | 5,419.40 mi (8,721.68 km) |
| Sioux City to Odorheiu Secuiesc | 5,336.41 mi (8,588.12 km) |
| Sioux City to Oltenita | 5,496.49 mi (8,845.75 km) |
| Sioux City to Onesti | 5,384.00 mi (8,664.72 km) |
| Sioux City to Oradea | 5,191.60 mi (8,355.07 km) |
| Sioux City to Orastie | 5,295.14 mi (8,521.70 km) |
| Sioux City to Oravita | 5,288.21 mi (8,510.56 km) |
| Sioux City to Orsova | 5,327.62 mi (8,573.98 km) |
| Sioux City to Otelu Rosu | 5,285.23 mi (8,505.76 km) |
| Sioux City to Otopeni | 5,453.98 mi (8,777.34 km) |
