Bang Rak Noi (, ) is one of the ten subdistricts (tambon) of Mueang Nonthaburi District, in Nonthaburi Province, Thailand. Neighbouring subdistricts are (from north clockwise) Om Kret, Tha It, Sai Ma, Bang Krang, Bang Len, Bang Rak Yai and Bang Rak Phatthana. In 2020, it had a total population of 21,366 people.
The subdistrict is subdivided into 6 administrative villages (muban).
The whole area of the subdistrict is covered by Bang Rak Noi Subdistrict Administrative Organization ().