Macadamia is a genus of four species of trees in the flowering plant family Proteaceae. They are indigenous to Australia, native to northeastern New South Wales and central and southeastern Queensland specifically. Two species of the genus are commercially important for their fruit, the macadamia nut. Global production in 2015 was 160,000 tonnes. Other names include Queensland nut, bush nut, maroochi nut, bauple nut and, in the US, they are also known as Hawaii nut. It was an important source of bushfood for the Aboriginal peoples.

The Proteaceae form a family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genera with about 1,660 known species. Australia and South Africa have the greatest concentrations of diversity. Together with the Platanaceae, Nelumbonaceae and in the recent APG IV system the Sabiaceae, they make up the order Proteales. Well-known Proteaceae genera include Protea, Banksia, Embothrium, Grevillea, Hakea, and Macadamia. Species such as the New South Wales waratah, king protea, and various species of Banksia, Grevillea, and Leucadendron are popular cut flowers. The nuts of Macadamia integrifolia are widely grown commercially and consumed, as are those of Gevuina avellana on a smaller scale.