Bang Khanun (, ) is one of the nine subdistricts (tambon) of Bang Kruai District, in Nonthaburi Province, Thailand. Neighbouring subdistricts are (from north clockwise) Bang Krang, Bang Si Thong, Wat Chalo, Maha Sawat and Bang Khun Kong. In 2020, it had a total population of 6,603 people.
The subdistrict is subdivided into 5 administrative villages (muban).
The whole area of the subdistrict is covered by Bang Khanun Subdistrict Administrative Organization ().