Psychonotis caelius, the small green banded blue, is a species of butterfly of the family Lycaenidae. It is found in New Guinea and adjacent islands and along the eastern coast of Australia.

Subspecies: 

• P. c. caelius (Aru, Australia)
• P. c. hanno (Grose-Smith, 1894) (New Britain)
• P. c. korion (H. H. Druce and Bethune-Baker, 1893) (Kai Islands)
• P. c. manusi (Rothschild, 1915) (Admiralty Islands)
• P. c. mayae (D´Abrera, 1971) (Louisiades)
• P. c. plateni (Grose-Smith and Kirby, [1896]) (Waigeu)
• P. c. plotinus (Grose-Smith and Kirby, [1896]) (Papua New Guinea)

Habitat: Psychonotis caelius are found in rainforests as well as parks, gardens and gullies with established host plants.

Host Plants: The larvae of Psychonotis caelius feed on the leaves of Alphitonia excelsa.