The manchineel tree (Hippomane mancinella), also known as the tree of death, is a species of flowering plant in the spurge family (Euphorbiaceae). Its native range stretches from tropical southern North America to northern South America.

The name manchineel (sometimes spelled manchioneel or manchineal), as well as the specific epithet mancinella, are from Spanish manzanilla ('little apple'), from the superficial resemblance of its fruit and leaves to those of an apple tree. It is also called beach apple.

A present-day Spanish name is manzanilla de la muerte, 'little apple of death'. This refers to the fact that manchineel is one of the most toxic trees in the world: It has milky-white sap that contains numerous toxins and can cause blistering. The sap is present in every part of the tree—bark, leaves, and fruit.

Hippomane mancinella grows up to 15 metres (49 feet) tall. It has reddish-grayish bark, small greenish-yellow flowers, and shiny green leaves. The leaves are simple, alternate, very finely serrated or toothed, and 5–10 centimetres (2–4 inches) long.

Spikes of small greenish flowers are followed by fruits, which are similar in appearance to an apple, are round-shaped and are green or greenish-yellow when ripe. The fruit is poisonous, as is every other part of the tree.

Manchineel is native to the Caribbean, the U.S. state of Florida, the Bahamas, Mexico, Central America, and northern South America.

The manchineel tree can be found on coastal beaches and in brackish swamps, where it grows among mangroves. It provides excellent natural windbreaks and its roots stabilize the sand, thus reducing beach erosion.

The manchineel tree is listed as an endangered species in Florida.