Ban Mai (, ) is one of the six subdistricts (tambon) of Bang Yai District, in Nonthaburi Province, Thailand. Neighbouring subdistricts are (from north clockwise) Nong Phrao Ngai, Bang Khu Rat, Bang Mae Nang, Bang Yai and Khlong Yong. In 2020, it had a total population of 9,206 people.
The subdistrict is subdivided into 11 administrative villages (muban).
The area of the subdistrict is shared by two local administrative organizations.