Mueang Chai Nat (, ) is the capital district (amphoe mueang) of Chai Nat province, central Thailand.
Neighbouring districts are (from the east clockwise) Sapphaya, Sankhaburi, Hankha, Wat Sing, and Manorom of Chai Nat province; and Takhli of Nakhon Sawan province.
On 29 April 1917 the district's name was changed from Mueang to Ban Kluai (à ¸Âà ¹Âà ¸²à ¸Âà ¸Âà ¸¥à ¹Âà ¸§à ¸¢). On 14 November 1938 it was renamed Mueang Chai Nat.
The district is divided into nine sub-districts (tambons), which are further subdivided into 81 villages (mubans). Chai Nat is a town (thesaban mueang) which covers tambon Nai Mueang and parts of Ban Kluai, Tha Chai, and Khao Tha Phra. There are a further eight tambon administrative organizations (TAO).