The Lewin's honeyeater is small to medium in size. It is dark greenish grey in colour, with a creamy yellow gape (fleshy corners of the mouth). It has large, yellowish crescent-shaped ear patches. In flight, the pale yellow edges of the flight feathers can be seen. The bill is black and the eye is blue-grey. Both sexes are similar in appearance. Young Lewin's honeyeaters are similar to the adults, but have brown eyes.