The Beast Within may refer to:

Film

• The Beast Within, a 1911 short silent film
• The Beast Within (film), a 1982 horror film directed by Philippe Mora
• The Beast Within (Danish: Menneskedyret), a 1995 film written and directed by Carsten Rudolf
• Virus Undead or Beast Within, a 2008 German horror film

Literature

• La Bête Humaine or The Beast Within, an 1890 novel by Émile Zola
• The Beast Within (novel), a 1981 novel by Edward Levy; basis for the film
• The Beast Within: A Gabriel Knight Mystery, a 1998 novel by Jane Jensen, a novelization of the eponymous computer game
• The Beast Within, a 2007 novel by Catherine MacPhail, the second installment in the Nemesis tetralogy
• The Beast Within, a 2011 by Lee Goldberg, William Rabkin and James Daniels, the seventh installment in The Dead Man series
• The Beast Within, a 2011 YA novel by Terry Spear
• The Beast Within: A Tale of Beauty's Prince, a 2014 YA novel based on Disney's Beauty and the Beast by Serena Valentino, the second installment in the Disney Villains series

Music

• "The Beast Within" (song), a remix of the 1990 Madonna song "Justify My Love"
• Beast Within, a 2008 album by Katra

Television

• "The Beast Within", a 1996 episode of The Adventures of Sinbad
• "The Beast Within", a 1996 episode of American Gothic
• "The Beast Within", a 1987 episode of Beauty and the Beast
• "The Beast Within", a 1995 episode of The Incredible Hulk
• "The Beast Within", a 1995 episode of Iron Man
• "The Beast Within", a 1994 episode of The Little Mermaid
• "The Beast Within", a 2017 episode of Lore
• "The Beast Within", a 1999 episode of The Lost World
• "The Beast Within", a 2009 episode of Monster Buster Club
• "The Beast Within", a 1997 episode of The New Adventures of Zorro
• "The Beast Within", a 1999 episode of Poltergeist: The Legacy
• "The Beast Within", a 1993 episode of Quantum Leap
• "The Beast Within", a 2014 episode of Remedy
• "Beast Within", a 2000 episode of Roswell Conspiracies: Aliens, Myths and Legends
• "The Beast Within", a 2016 episode of Scream Street
• "The Beast Within", a 2019 episode of Shadowhunters
• "The Beast Within", a 1997 episode of Street Fighter
• "The Beast Within", a 2004 episode of Teen Titans
• "The Beast Within", a 1986 episode of Teen Wolf
• "The Beast Within", a 2004 episode of Ultimate Muscle: The Kinnikuman Legacy

Other uses

• The Beast Within: A Gabriel Knight Mystery, a 1995 computer adventure game
• The Beast Within: The Making of Alien, a 2003 direct-to-video documentary about the 1979 film Alien featured in the Alien Quadrilogy DVD set