Bang Khun Thian is one of the 50 districts (khet) of Bangkok, Thailand. Its neighbors, clockwise from the north, are Bang Bon, Chom Thong, and Thung Khru Districts of Bangkok, Phra Samut Chedi district of Samut Prakan province and Mueang Samut Sakhon district of Samut Sakhon province. Bang Khun Thian is Bangkok's southernmost district, and the only one bordering the Bay of Bangkok.