Sanam Chai Khet (Thai: สนามชัยเขต, pronounced [sā.nǎːm t͡ɕʰāj kʰèːt]) is a district (amphoe) in the eastern part of Chachoengsao province, central Thailand.

Being part of Phanom Sarakham district, on 6 January 1966 the three tambons, Khu Yai Mi, Tha Kradan, and Tha Takiap, were split off to form the minor district (king amphoe) Sanam Chai (สนามไชย).

[1] It was renamed Sanam Chai Ket on 14 December 1972,[2] and upgraded to a full district on 28 June 1973.

Sanam Chai Khet is divided into four sub-districts (tambons), which are further subdivided into 70 administrative villages (mubans).

There is one sub-district municipality (thesaban tambon) in the district, Sanam Chai Khet (Thai: เทศบาลตำบลสนามชัยเขต) consisting of parts of sub-district Khu Yai Mi.