In Greek mythology, Dryas was the son of King Lycurgus of Thrace. He was killed when his father went insane and mistook him for a patch of ivy, a plant holy to the god Dionysus.

Lycurgus had imprisoned all of Dionysus' followers, the Maenads, and forced Dionysus to flee his kingdom. Dionysus took refuge with Thetis the sea nymph, sent a drought to Thrace, and drove Lycurgus insane. An oracle predicted that the land would stay dry and barren as long as Lycurgus was alive, so his people had him drawn and quartered. With Lycurgus dead, Dionysus lifted the curse.

In botany, Dryas is a plant genus, family Rosaceae.

In climatology, Dryas is a name given to several climatic periods in which the plant Dryas flourished. See, for example, Younger Dryas.