Areca catechu is a species of palm native to the Philippines cultivated for areca nuts. It was carried widely through the tropics by the Austronesian migrations and trade since at least 1500 BCE due to its use in betel nut chewing. It is widespread in cultivation and is considered naturalized in much of tropical Asia and in Taiwan, southern China (Guangxi, Hainan, Yunnan), Madagascar, parts of the Pacific Islands, and also in the West Indies.

Its fruits (called areca nuts or betel nuts) are chewed together with slaked lime and betel leaves for their stimulant and narcotic effects.

Common names in English include areca palm, areca nut palm, betel palm, betel nut palm, Indian nut, Pinang palm and catechu. This palm is commonly called the betel tree because its fruit, the areca nut, which are often chewed along with the betel leaf, a leaf from a vine of the family Piperaceae.

The species was first published by Carl Linnaeus in his book Species Plantarum on page 1189 in 1753.

Areca catechu is a medium-sized palm tree, growing straight to 20 m (66 ft) tall, with a trunk 10–15 cm (4–6 in) in diameter. The leaves are 1.5–2 m (4.9–6.6 ft) long, pinnate, with numerous, crowded leaflets.

The seed contains alkaloids such as arecaidine and arecoline, which, when chewed, are intoxicating and slightly addictive. The seed also contains condensed tannins (procyanidins) called arecatannins, which are carcinogenic.

The antibacterial activity of the seed has been studied.

Areca catechu is grown for its commercially important seed crop, the areca nut, which is the main component of the practice of betel nut chewing. It is popular throughout Southeast Asia, South Asia, Taiwan, Papua New Guinea, the Solomon Islands, parts of southern China, Madagascar, and the Maldives. The nut itself can be addictive and has direct link to oral cancers. Chewing areca nut is a cause of oral submucous fibrosis, a premalignant lesion which frequently progresses to mouth cancer.