Kaō (鹿央町 Kaō-machi) was a town located in Kamoto District, Kumamoto, Japan.
On January 15, 2005 Kaō, along with the towns of Kahoku, Kamoto and Kikuka, all from Kamoto District, was merged into the expanded city of Yamaga and no longer exists as an independent municipality.
As of 2003, the town had an estimated population of 5,099 and a density of 162.03 persons per km². The total area was 31.47 km².