Mephistopheles (also Mephisto, Mephistophilus, Mephist and Mephistophilis as referred to in the original text) is a name given to one of the chief demons of Christian mythology that figure in European literary traditions. The name is frequently used as an alternative form of Satan or the Devil. Because the name Mephistopheles evolved during the Renaissance, Mephistopheles makes no appearance in the Bible. However, according to a certain biblical texts relating to Christian mysticism, and a number of related works written during the 17th century, Mephistopheles was the first to join with Lucifer during the rebellion against God at the beginning of time. When the rebel angels were banished from Heaven, Mephistopheles was the second to fall, after Lucifer. In exchange for his loyalty Lucifer granted him power in Hell, appointing him as his second-in-command.

Mephistopheles appears most prominently in the legend of Faustus, a man who sells his soul to the Devil. This legend was famously recorded in Christopher Marlowe's play from the 1590s, The Tragical History of Doctor Faustus, and in the classic 19th century drama Faust (Part 1 and Part 2) by the influential German writer and humanist Johann Wolfgang von Goethe.

Mephistopheles is known throughout Goethe's book as a "fallen angel" himself, as he clearly states to Faustus. He rebels against the authority of God and is thrown out of heaven into hell.

Mephisto is also the title of a book by contemporary Irish writer John Banville. The novel treats the descent of a young math prodigy, and burn victim, Gabriel Swann, into a personal hell, accompanied by various Mephisotopholean characters, including Felix and Mr. Kasperl.

The meaning, if any, of the name "Mephistopheles" is unknown, although the historical evidence suggests that it was invented by the anonymous author of the German chapbook that made the Faust story famous. Many attempts have been made to construct etymologies from Greek or Hebrew, but with no plausible results.

Mephistopheles in popular culture

In Marvel Comics, Mephisto is a prominent demon.

On Xena: Warrior Princess, Mephistopheles, in episode 6x02 (The Haunting of Amphipolis), is the original ruler of Hell. He is then replaced by Lucifer.

Mephistopheles appears in several video games. Mephisto is one of the three 'Prime Evils' in Blizzard Entertainment's Diablo series along with Diablo and Baal. In Dungeons & Dragons he is an archdevil, lord of the 8th layer of the Nine Hells of Baator—Cania. In this role, it is revealed that he is the primary villain in the PC game Hordes of the Underdark, an expansion pack to Neverwinter Nights.

On Beethoven's Last Night, concept album from Trans-Siberian Orchestra, Mephistopheles represents the devil himself.

Mephistopheles is referenced in "Wrapped Around Your Finger" from the Police album Synchronicity.