Lady's Slipper, the common name of a genus of flowering plants of the orchid family. Lady's slippers grow chiefly in woodlands and marshes in temperate regions of the Northern Hemisphere. There are about 50 species. The flowers of all species have an enlarged lower petal in the shape of an inflated sac that bears a resemblance to a slipper. The plants grow from 6 to 30 inches (15 to 75 cm) tall, depending on the species. Common species of the United States include the showy lady's slipper, the yellow lady's slipper, and the moccasin flower.

Lady's slippers make up the genus Cypripedium of the family Orchidaceae. The showy lady's slipper is C. reginae; the yellow, C. calceolus; the moccasin flower, C. acaule.