The crescent honeyeater is a passerine bird of the honeyeater family Meliphagidae native to southeastern Australia. A member of the genus Phylidonyris, it is most closely related to the common New Holland honeyeater and the white-cheeked honeyeater. Two subspecies are recognized, with P. p. halmaturinus restricted in range to Kangaroo Island and the Mount Lofty Ranges in South Australia.