Diabolical

Diabolical may refer to:


 * Evil, the profound immorality, especially when regarded as a supernatural force, for example in religious belief
 * The Devil, believed in many religions, myths and cultures to be a supernatural entity that is the personification of evil and the enemy of God and humankind
 * Diabolical (album), a 1998 studio album by the Swedish melodic black metal band Naglfar
 * Diabolical, a 2001 studio album by the American rapper Mr. Lucci
 * The Diabolical, a 2015 American science fiction horror film
 * The Boys Presents: Diabolical, a 2022 American adult animated superhero anthology spin-off of the television series The Boys