Banksia speciosa, commonly known as the showy banksia, is a species of large shrub or small tree in the family Proteaceae. It is found on the south coast of Western Australia between Hopetoun (33°57′ S) and the Great Australian Bight, growing on white or grey sand in shrubland. Reaching up to 8 m (26 ft) in height, it is a single-stemmed plant that has thin leaves with prominent triangular "teeth" along each margin, which are 20–45 cm (7.9–17.7 in) long and 2–4 cm (0.8–1.6 in) wide. The prominent cream-yellow flower spikes known as inflorescences appear throughout the year. As they age they develop up to 20 follicles each that store seeds until opened by fire. Though widely occurring, the species is highly sensitive to dieback and large populations of plants have succumbed to the disease.

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.