基亚索是瑞士的城镇，位于该国南部，由提契诺州负责管辖，面积5.33平方公里，海拔高度230米，2011年人口7,776，八成居民信奉罗马天主教，人口密度每平方公里1,467人。

• （意大利文） Official municipality website

Chiasso (Italian pronunciation: [ˈkjasso], or commonly in Lombard: Ciass [tʃasː]) is a municipality in the district of Mendrisio in the canton of Ticino in Switzerland.

As the southernmost of Switzerland's municipalities, Chiasso is located at the border with Italy, in front of Ponte Chiasso (a Frazione of Como, Italy). The municipality of Chiasso includes the villages of Boffalora, Pedrinate and Seseglio.