A triple goddess is a term used to describe any goddess who appears as a triad. In ancient Indo-European mythologies, various goddesses or demi-goddesses appear as a triad, either as three separate beings who always appear as a group (the Greek Moirae, Charites, Erinyes and a trio of Norse Norns) or as a single deity who is commonly depicted in three aspects (Greek Hecate and the cult image of Latin Diana Nemorensis, of whom Hecate is one part).
Often it is ambiguous whether a single being or three are represented, as is the case with the Irish Brighid and her two sisters, also called Brighid, or the Morrígan who is known by at least three or four different names. In most ancient portrayals of triple goddesses, the separate deities perform different yet related functions, and there is no obvious difference in their ages.
In Wicca and related Neopagan religions, the Triple Goddess is, along with the Horned God, held in particular reverence, and her three aspects are most often portrayed as being of different ages: Maiden, Mother and Crone, an idea which was popularized in the modern period by Robert Graves.