Sai Yai (Thai: ไทรใหญ่, pronounced [sāj jàj]) is one of the seven subdistricts (tambon) of Sai Noi District, in Nonthaburi Province, Thailand.

Neighbouring subdistricts are (from north clockwise) Sam Mueang, Rat Niyom, Khun Si, Bang Phasi, Sai Ngam and Ninlaphet.

[2] The subdistrict is subdivided into 11 administrative villages (muban).

[3][4] The whole area of the subdistrict is covered by Sai Yai Subdistrict Administrative Organization (องค์การบริหารส่วนตำบลไทรใหญ่).

This Nonthaburi Province location article is a stub.