A pentacle (also spelled and pronounced as pantacle in Thelema, following Aleister Crowley, though that spelling ultimately derived from Éliphas Lévi) is a talisman that is used in magical evocation, and is usually made of parchment, paper, cloth, or metal (although it can be of other materials), upon which a magical design is drawn. Protective symbols may also be included (sometimes on the reverse), a common one being the six-point form of the Seal of Solomon.

Pentacles may be sewn to the chest of one's garment, or may be flat objects that hang from one's neck or are placed flat upon the ground or altar. Pentacles are almost always shaped as disks or flat circles. In the Hermetic Order of the Golden Dawn, though, a pentacle is placed within the triangle of evocation.

Many varieties of pentacle can be found in the grimoire called the Key of Solomon. Pentacles are also used in the neopagan magical religion called Wicca, alongside other magical tools. In the Hermetic Order of the Golden Dawn and Wicca, pentacles symbolize the classical element earth. In the 1909 Rider–Waite–Smith tarot deck (the pentacles of which were designed by Arthur Edward Waite), and subsequent tarot decks that are based upon it, and in Wicca, pentacles prominently incorporate a pentagram in their design. This form of pentacle is formed upon a disk which may be used either upon an altar or as a sacred space of its own.