Mae Chai (Thai: แม่ใจ, pronounced [mɛ̂ː t͡ɕāj]) is a small town and subdistrict (tambon) in Mae Chai District, in Phayao Province, Thailand.

[2] To the north along the highway are Pa Faek and then Mae Yen across into Chiang Rai Province.

It lies partly within Mae Puem National Park.

In the 1950s, the area was reported to be heavily forested but it saw an extraordinary growth in rice production in the 1990s.

[3] The tambon also has great conditions with temperature and rainfall for highland wheat production, which has been exploited in villages such as Pha Daeng with improved technology.