Bang Pa-in was established in the Ayutthaya era in the name Khwaeng U Thai. In Rattanakosin eraKhwaeng U Thai was divided to be Khwaeng U Thai Noi and U Thai Yai. In 1910 Khwaeng U Thai Noi was changed status and renamed to Phra Ratchawang district. The district name was changed again to Bang Pa-in after the name of Bang Pa-in island in 1915.
The district is subdivided into 18 subdistricts (tambon), which are further subdivided into 149 villages (muban). There are 9 municipal (thesaban) areas, and 9 Tambon administrative organizations (TAO).