Originally named Pak Bong after its central subdistrict, the district was renamed to Pa Sang in 1953.1
Administration
The district is subdivided into 9 subdistricts (tambon), which are further subdivided into 86 villages (muban). There are three subdistrict municipalities (thesaban tambon) - Mae Raeng and Muang Noi cover the whole same-named tambon, and Pa Sang parts of tambon Pa Sang and the whole tambon Pak Bong. There are further 5 Tambon administrative organizations (TAO).