Cortaderia selloana, commonly known as pampas grass, is a flowering plant native to southern South America, including the pampas after which it is named.

It is a tall grass, growing in dense tussocks that can reach a height of 3 m (10 ft). The leaves are evergreen, long and slender, 1–2 m (3 ft 3 in–6 ft 7 in) long and 1 cm broad, with very sharp edges. The leaves are usually bluish-green, but can be silvery grey. The flowers are produced in a dense white panicle 20–40 cm (8–16 in) long on a 2–3 m (6 ft 7 in–9 ft 10 in) tall stem.

It was named by Alexander von Humboldt in 1818, after the German botanist and naturalist Friedrich Sellow, who studied the flora of South America, especially that of Brazil.