In the eastern Indian Ocean they are found along the eastern coast of Africa from Somalia to South Africa and across the Indian Ocean as far north as India and Sri Lanka and into the Pacific Ocean where they extend as far north as Kashiwa-jima in southern Japan, south to Lord Howe Island and east to Mangarava in French Polynesia.

In Western Australia it is found at the Rowley Shoals and Scott Reef.

[2] The bluelashed butterflyfish was first formally described in 1831 by the French anatomist Georges Cuvier (1769–1832).

[4] The specific name honours the English naturalist Edward Turner Bennett (1797–1836) who had the type specimen of this species shown to Cuvier.

[5] Like the other butterflyfishes with angular yellow bodies with black eyestripes and, except for this species which is regarded as the most basal of them, a single differently-colored patch, it belongs in the subgenus Tetrachaetodon.