The areca nut or betel nut is the fruit of the areca palm, which grows in much of the tropical Pacific, South Asia, Southeast Asia, and parts of east Africa. It is not to be confused with betel leaves that are often used to wrap it.

Areca is a genus of 51 species of palms in the family Arecaceae, found in humid tropical forests from the islands of the Philippines, Malaysia and India, across Southeast Asia to Melanesia. The generic name Areca is derived from a name used locally on the Malabar Coast of India.