Elaeis guineensis is a species of palm commonly just called oil palm but also sometimes African oil palm or macaw-fat. The first Western person to describe it and bring back seeds was the French naturalist Michel Adanson.

It is native to west and southwest Africa, specifically the area between Angola and The Gambia; the species name, guineensis, refers to the name for the area called Guinea, and not the modern country Guinea now bearing that name. The species is also now naturalised in Madagascar, Sri Lanka, Malaysia, Indonesia, Central America, Cambodia, the West Indies, and several islands in the Indian and Pacific Oceans. The closely related American oil palm E. oleifera and a more distantly related palm, Attalea maripa, are also used to produce palm oil.

E. guineensis was domesticated in West Africa along the south-facing Atlantic coast. There is insufficient documentation and as of 2019^[update] insufficient research to make any guesses as to when this occurred. Human use of oil palms may date as far back as 5,000 years in Egypt; in the late 1800s, archaeologists discovered palm oil in a tomb at Abydos, Egypt, dating back to 3000 BCE (but this information needs further investigation, due to recent reviews. The oil found in Abydos may be just date oil or even animal fats).

It is the principal source of palm oil. Oil palms can produce much more oil per unit of land area than most other oil-producing plants (about nine times more than soy and 4.5 times more than rapeseed).

E. guineensis is monocotyledonous. Mature palms are single-stemmed and grow to 20 meters (66 ft) tall. The leaves are pinnate and reach 3–5 m (10–16+1⁄2 ft) long. A young palm produces about 30 leaves a year. Established palms over 10 years produce about 20 leaves a year. The flowers are produced in dense clusters; each individual flower is small, with three sepals and three petals.

The palm fruit takes 5–6 months to develop from pollination to maturity. It is reddish, about the size of a large plum, and grows in large bunches. Each fruit is made up of an oily, fleshy outer layer (the pericarp), with a single seed (the palm kernel), also rich in oil. When ripe, each bunch of fruit weighs between 5 and 30 kg (11 and 66 lb) depending on the age of the palm tree.

For each hectare of oil palm, which is harvested year-round, the annual production averages 20 tonnes ^{[citation needed]} of fruit yielding 4,000 kg of palm oil and 750 kg ^{[citation needed]} of seed kernels yielding 500 kg of high-quality palm kernel oil, as well as 600 kg of kernel meal. Kernel meal is processed for use as livestock feed.

All modern, commercial planting material consists of tenera palms or DxP hybrids, which are obtained by crossing thickshelled dura with shell-less pisifera. Although common commercial germinated seed is as thick-shelled as the dura mother palm, the resulting palm will produce thin-shelled tenera fruit. An alternative to germinated seed, once constraints to mass production are overcome, are tissue-cultured or "clonal" palms, which provide true copies of high-yielding DxP palms.^{[citation needed]}