The White-necked Heron is a large heron with a white head and a long white neck with a double line of black spots running down the front. The upperparts of the body are dark slatey-grey, with plum-coloured nuptial plumes on the back and breast during the breeding season. Underparts are grey streaked with white. The bill is black, the naked facial skin is blue or yellow, the eyes are green, and the legs and feet are black.