The Yellow-crowned Night Heron, Nycticorax violaceus or Nyctanassa violacea, is a smaller heron, similar in appearance to the Black-crowned Night Heron.

Adults are 61 cm long and weigh 625 g. They have a white crown and back with the remainder of the body grayish, red eyes and short yellow legs. They have a white stripe below the eye. Juveniles resemble young Black-crowned Night-Herons, being mainly brown flecked with white or gray.

Their breeding habitat is swamps and marshes from the eastern United States to north-eastern South America. They often nest in colonies, usually on platforms of sticks in trees or shrubs overhanging water. they lay 3–5 pale blue-green eggs.

In warmer locations, some are permanent residents; others migrate to Central America and the West Indies. They may occasionally wander north to the lower Great Lakes or Ontario after the breeding season.

A related heron was endemic to Bermuda (Bermuda Night Heron), but became extinct following human colonisation. American Yellow-crowned Night Herons have been introduced to fill its ecological niche.

These birds stalk their prey or wait in ambush at the water's edge, mainly at night. They mainly eat crustaceans, mollusks, frogs, aquatic insects and small fish.