The district was created on 23 November 1919, consisting of two
tambons from Selaphum District, two from
Kamalasai and two from
Kuchinarai. Another
tambon was taken from Din Daeng District, which was abolished on the same day. The other six
tambons from
Din Daeng were assigned to Saeng Badan District (now a subdistrict in
Somdet district). In 1939 the district, as well as the main
tambon, were renamed
Waeng. The district name was changed back to
Phon Thong in 1953. ==Administration==