The Belted Kingfisher (Megaceryle alcyon) is a large, conspicuous and noisy water kingfisher, the only member of that group commonly found in the northern United States and Canada. It is the bird depicted on the 1986 series Canadian $5 note. All kingfishers were formerly placed in one family, Alcedinidae, but recent research suggests that this should be divided into three. All six American kingfishers, together with three Old World species, make up the new family Cerylidae.

The Belted Kingfisher is a stocky, medium-sized bird that measures between 28–35 cm (11–14 in) in length with a wingspan of between 48–58 cm (19–23 in). Birds usually weigh between 140–170 g (4.94–6 ounces).

This species features a large head topped with a shaggy crest and the bill is long and heavy. The base of the bill is grey with the rest in black. Males and females of this species display reverse sexual dimorphism, with the female more brightly colored than the male. Both adult males and females have a slate blue head, large, white collar, a large blue band on the breast with white underparts. The back and wings are the same slate blue with black tips. The female features a rufous band across the upper belly that extands down the flanks. Juveniles of this species are similar to adults but both males and females feature the rufous band on the upper belly. Juvenile males will have a rufous band that is somewhat mottled while the band on females will be much thinner than that on adult females.

The Megaceryle large green kingfishers were formerly placed in Ceryle with the Pied Kingfisher, but the latter is closer to the Chloroceryle American green kingfishers. The Belted Kingfisher's closest living relative is the Ringed Kingfisher (M. torquata), and these two in all probability originated from an African Megaceryle which colonized the Americas.

This bird's breeding habitat is areas near inland bodies of waters or coasts across most of Canada, Alaska and the United States. They migrate from the northern parts of its range to the southern United States, Mexico, Central America, the West Indies and northern South America in winter. During migration they may stray far from land; the species is recorded as an accidental visitor on oceanic islands such as Clarion, and has occurred as an extremely rare vagrant in Iceland, Ireland and the UK.

They leave their breeding habitat when the water freezes; in warmer parts of its range, these birds are permanent residents. Still, a few individuals may linger even in the coldest winters except in the Arctic, if there are open bodies of water remaining.

The Belted Kingfisher is often seen perched prominently on trees, posts, or other suitable "watchpoints" close to water before plunging in head first after its fish prey. They also eat small crustaceans, frogs, aquatic insects, small mammals, lizards and berries[verification needed].

These birds nest in a horizontal tunnel made in a river bank or sand bank. The female lays 5 to 8 eggs. Both parents excavate the tunnel, incubate the eggs and feed the young.