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

Neighbouring subdistricts are (clockwise from north) Khlong Khwang, Lahan, Bang Bua Thong, Thawi Watthana and Khun Si.

[1][2] The subdistrict is subdivided into 11 administrative villages (muban).

[3][4] The area of the subdistrict is shared by two local administrative organizations.

This Nonthaburi Province location article is a stub.