Huai Sai () is a tambon (subdistrict) of San Kamphaeng District, in Chiang Mai Province, Thailand. In 2020, it had a total population of 5,964 people.
The tambon is subdivided into 8 administrative villages (muban).
The whole area of the subdistrict is covered by the subdistrict municipality (Thesaban Tambon) Huai Sai (à ¹Âà ¸Âà ¸¨à ¸Âà ¸²à ¸¥à ¸Âà ¸³à ¸Âà ¸¥à ¸«à ¹Âà ¸§à ¸¢à ¸Âà ¸£à ¸²à ¸¢).