Cattleya /ˈkætliːə/ is a genus of 113 species of orchids from Costa Rica to tropical South America. The genus was named in 1824 by John Lindley after Sir William Cattley who received and successfully cultivated specimens of Cattleya labiata that were used as packing material in a shipment of other orchids made by William Swainson. The genus is abbreviated C in trade journals.

They are widely known for their large, showy flowers, and were used extensively in hybridization for the cut-flower trade until the 1980's when pot plants became more popular. This genus and the numerous hybrids come close, through their beauty, to the idealized picture we have of the orchids. The flowers of the hybrids can vary in size from 5 cm to 15 cm or more. They occur in all colors except true blue and black.

The typical flower has three rather narrow sepals and three usually broader petals: two petals are similar to each other, and the third is the quite different conspicuous lip, featuring various markings and specks and an often frilly margin. At the base, the margins are folded into a tube. Each flower stalk originates from a pseudobulb. The number of flowers varies; it can be just one or two, or sometimes up to ten.