Maha Sawat (, ) is one of the nine subdistricts (tambon) of Bang Kruai district, in Nonthaburi province, Thailand. Neighbouring subdistricts are (from north clockwise) Bang Khun Kong, Bang Khanun, Wat Chalo, Taling Chan, Chimphli, Plai Bang and Bang Khu Wiang. In 2020 it had a total population of 20,697 people.
The subdistrict is subdivided into 7 administrative villages (muban).
The area of the subdistrict is shared by two local administrative organizations.