| Seia to Navodari | 1,857.76 mi (2,989.77 km) |
| Seia to Negresti-Oas | 1,613.95 mi (2,597.40 km) |
| Seia to Nehoiu | 1,741.42 mi (2,802.55 km) |
| Seia to Ocna Mures | 1,625.25 mi (2,615.59 km) |
| Seia to Odobesti | 1,777.91 mi (2,861.26 km) |
| Seia to Odorheiu Secuiesc | 1,693.70 mi (2,725.75 km) |
| Seia to Oltenita | 1,761.27 mi (2,834.50 km) |
| Seia to Onesti | 1,763.67 mi (2,838.35 km) |
| Seia to Oradea | 1,537.75 mi (2,474.76 km) |
| Seia to Orastie | 1,591.82 mi (2,561.79 km) |
| Seia to Oravita | 1,516.38 mi (2,440.37 km) |
| Seia to Orsova | 1,550.76 mi (2,495.71 km) |
| Seia to Otelu Rosu | 1,549.99 mi (2,494.47 km) |
| Seia to Otopeni | 1,731.56 mi (2,786.68 km) |
| Seia to Ovidiu | 1,855.41 mi (2,985.99 km) |
