| Seia to Orbetello | 987.61 mi (1,589.40 km) |
| Seia to Oria | 1,327.28 mi (2,136.05 km) |
| Seia to Oristano | 859.86 mi (1,383.82 km) |
| Seia to Orta Nova | 1,221.11 mi (1,965.18 km) |
| Seia to Orte | 1,047.46 mi (1,685.72 km) |
| Seia to Ortona | 1,150.19 mi (1,851.06 km) |
| Seia to Orvieto | 1,033.91 mi (1,663.91 km) |
| Seia to Orzinuovi | 953.96 mi (1,535.25 km) |
| Seia to Osimo | 1,105.80 mi (1,779.61 km) |
| Seia to Ospitaletto | 963.30 mi (1,550.29 km) |
| Seia to Ostuni | 1,322.51 mi (2,128.38 km) |
| Seia to Ottaviano | 1,160.21 mi (1,867.17 km) |
| Seia to Ovada | 880.09 mi (1,416.37 km) |
| Seia to Ozieri | 876.41 mi (1,410.44 km) |
| Seia to Paceco | 1,094.87 mi (1,762.02 km) |
