Seranishi (世羅西町 Seranishi-chō) was a town located in Sera District, Hiroshima Prefecture, Japan.
As of 2003, the town had an estimated population of 3,919 and a density of 56.68 persons per km². The total area was 69.14 km².
On October 1, 2004, Seranishi, along with the town of Kōzan (also from Sera District), was merged into the expanded town of Sera and no longer exists as an independent municipality.