卡索（西班牙语：Caso），是西班牙阿斯图里亚斯的一个市镇。总面积308平方公里，总人口1962人（2001年），人口密度6人/平方公里。

Caso (Asturian: Casu) is a municipality in the Spanish Principality of Asturias. It shares a boundary to the North with Piloña; to the East with Ponga; to the South with León and to the West with Sobrescobio and Laviana.

Most of the inhabitants of Caso live in the Nalón Valley, on which the largest town is the capital El Campu. The town is divided in two neighbourhoods: L'Arrobiu and El Barru.