A magician, also known as an archmage, mage, magus, magic-user, spellcaster, enchanter/enchantress, sorcerer/sorceress, warlock, witch, or wizard, is someone who uses or practices magic derived from supernatural, occult, or arcane sources. Magicians enjoy a rich history in mythology, legends, fiction, and folklore, and are common figures in works of fantasy, such as fantasy literature and role-playing games.

People who work magic are called by several names in fantasy works, and terminology differs widely from one fantasy world to another. While derived from real-world vocabulary, the terms: magician, mage, magus, enchanter/enchantress, sorcerer/sorceress, warlock, witch, and wizard, each have different meanings depending upon context and the story in question. Archmage is used in fantasy works to indicate a powerful magician or a leader of magicians.

Enchanters typically practice a type of imbued magic that produces no permanent effects on objects or people and are temporary, or of an indefinite duration, or which may require some item or act, to nullify or reverse. For example, this could include enchanting a weapon or tool to be more (or less) effective, enchanting a person or object to have a changed shape or appearance, creating illusions intended to deceive the observer, compelling a person to perform an action they might not normally do, or attempting to charm or seduce someone. For instance, the Lady of the Green Kirtle in C. S. Lewis's The Silver Chair can transform herself into a large green serpent. She also enchants Rilian, compelling him to forget his father and Narnia. And when that enchantment is broken, she attempts further enchantments with a sweet-smelling smoke and a thrumming musical instrument to attempt to baffle him and his rescuers into forgetting them again.

The term sorcerer has moved from meaning a fortune-teller, or "one who alters fate", to meaning a practitioner of magic who can alter reality. They are also sometimes shown as able to conjure supernatural beings or spirits, or to "animate" inanimate objects, such as in The Sorcerer's Apprentice. Due to this perception of their powers, this character may be depicted as feared, or even seen as evil. Villainous sorcerers were so crucial to pulp fantasy that the genre in which they appeared was dubbed "sword and sorcery", where typically the hero (or anti-hero) would be the sword-wielder, thus leaving the sorcery for his opponent.

Witch (an—often female—practitioner of witchcraft) and wicked (an adjective meaning "bad, evil, false") are both derivative terms from the word, wicca (an Old English word with varied meanings, including soothsayer, astrologer, herbalist, poisoner, seductress, or devotee of supernatural beings or spirits). L. Frank Baum combined these terms in naming the Wicked Witch of the West, and other witches in the Land of Oz. Baum named Glinda the "Good Witch of the South" in The Wonderful Wizard of Oz. In The Marvelous Land of Oz, he dubbed her "Glinda the Good," and from that point forward and in subsequent books, Baum referred to her as a sorceress rather than a witch to avoid the term that was more regarded as evil. In modern fiction, a witch may be depicted more neutrally, such as the female witches (comparable to the male wizards) in the Harry Potter series of books by J. K. Rowling.

In medieval chivalric romance, the wizard often appears as a wise old man and acts as a mentor, with Merlin from the King Arthur stories being a prime example. Wizards such as Gandalf in The Lord of the Rings and Albus Dumbledore from Harry Potter are also featured as mentors, and Merlin remains prominent as both an educative force and mentor in the modern works of Arthuriana.

Wizards can be cast similarly to the absent-minded professor: being foolish and prone to misconjuring. They can also be capable of great magic, both good and evil. Even comical magicians are often capable of great feats, such as those of Miracle Max in The Princess Bride; although he is a washed-up wizard fired by the villain, he saves the dying hero. Other wizards, such as Saruman from The Lord of the Rings or Lord Voldemort from Harry Potter, can appear as hostile villains.

Ursula K. Le Guin's A Wizard of Earthsea explored the question of how wizards learned their art, introducing to modern fantasy the role of the wizard as the protagonist. This theme has been further developed in modern fantasy, often leading to wizards as heroes on their own quests. Such heroes may have their own mentor, a wizard as well.