The Strong-billed Honeyeater is the larger of the two Tasmanian Melithreptus honeyeaters. It has a large, almost straight black bill with a heavy base and sharply pointed tip, as well as a strongly built neck and shoulders. The head is black, with a distinctive white crescent across the back of the neck, white-green eye-skin and a white chin and throat with a small black wedge on the underside of the bill. The upperparts are olive-grey to green above with the underparts a dull grey-green. Young birds resemble adults, but have a lemon-yellow tinge to the back of the neck, a browner head and a yellow-orange bill and eye-skin. In behaviour, this species resembles treecreepers, moving up and down the trunks of trees in search of insects. It is often seen with other honeyeaters, especially the related Black-headed Honeyeater, as well as pardalotes and thornbills, and is very noisy and gregarious when feeding.