The nankeen night heron has a heavy black bill, which is similar in length as its head. The face is white with a cinnamon tint, and the nape and crown of breeding adults is a grey-black. During the breeding season, there are also usually two or three thin, white plumes from the crown in a downward direction to the neck. These are tipped with black when newly grown. The heron has a rich chestnut colour across the upperparts, and the colours are more intense in the breeding season. The underparts of the nankeen night heron are white, and there is a gradual blend of the chestnut colour and the white on its neck and upper breast. The back, tail, and upper wing of the bird are a rich rufous colour. The iris is of a straw yellow and can be tinged with orange during the breeding season, while the legs and feet are a creamy yellow. Their legs are relatively shorter than that of other herons, and can become bright pink during courtship and early breeding.