Kao Liao (, ) is a district (amphoe) of Nakhon Sawan province, central Thailand.
The minor district (king amphoe) was created on 1 October 1969, when five tambons were split off from Banphot Phisai district. It was upgraded to a full district on 28 June 1973.
Neighboring districts are (from the north clockwise): Banphot Phisai of Nakhon Sawan province; Pho Thale of Phichit province; Chum Saeng and Mueang Nakhon Sawan of Nakhon Sawan.
The district is divided into five sub-districts (tambons), which are further subdivided into 44 villages (mubans). Kao Liao is a township (thesaban tambon) which covers the whole tambon Kao Liao. There are a further four tambon administrative organizations (TAO) in the district.