Seidan, Hyōgo

Seidan (西淡町) was a town located in Mihara District, Hyōgo Prefecture, Japan.

As of 2003, the town had an estimated population of 12,004 and a density of 214.40 persons per km2. The total area was 55.99 km2.

On January 11, 2005, Seidan, along with the towns of Mihara, Midori and Nandan (all from Mihara District), was merged to create the city of Minamiawaji.