The Glossy Ibis has a reddish-brown neck and a bronze-brown body with a metallic iridescent sheen on its wings. It features a distinctive long, downturned bill that is olive-brown in color, and blue-gray facial skin with a white line extending around the eyes. The eyes, legs, and feet are brown. While both sexes have similar plumage, males are generally larger. On average, the Glossy Ibis measures 55–65 cm in length, has a wingspan of 80–95 cm, and weighs about 500–800 grams. During the breeding season, the plumage becomes more vibrant, with a rich chestnut color on the neck, mantle, shoulders, and underparts, and a purple-green sheen on the head, upperparts, tail, and wings. The facial skin turns pale blue during courtship and fades to dark purple afterward. Juveniles have dark plumage similar to adults, but nestlings start with a pink bill that gradually changes to olive-brown from the tip.