Kiso District is a district located in Nagano Prefecture, Japan.
As of November 1, 2005, the district has an estimated population of 34,759. The total area is 1,546.26 km².
Historically, the district was once known as Nishichikuma District until May 1, 1968.
There are only three towns and three villages within the district.
Agematsu
Kiso Town
Nagiso
Kiso Village
Ōkuwa
Ōtaki