Crazy may refer to:

• Insanity
• Crazy Magazine (1973–1983), a comic magazine
• Crazy (documentary), a 1999 documentary by Heddy Honigmann
• Crazy (film), a 2000 film directed by Hans-Christian Schmid
• Crazy, a novel by Benjamin Lebert
• "Crazy" (Law & Order: Criminal Intent episode) (2002)
• C.R.A.Z.Y., a 2005 film directed and co-written by Jean-Marc Vallée
• Crazy (2007 film), directed by Rick Bieber

In popular music:

• Crazy by Julio Iglesias
• Crazy (calypsonian), a calypso singer from Trinidad and Tobago
• "Crazy" (Willie Nelson song) (1961), popularized by Patsy Cline
• "Crazy" (Five Star song) (1984)
• "Crazy" (Kenny Rogers song) (1985)
• "Crazy" (Icehouse (band) song) (1987)
• "Crazy" (The Boys song) (1990)
• "Crazy" (Seal song) (1991), later covered by Alanis Morissette
• "Crazy" (Barenaked Ladies song) (1992)
• "Crazy" (Aerosmith song) (1994)
• "Crazy" (Eternal song) (1994)
• "Crazy" (Alana Davis song) (1998)
• "Crazy" (Leah Haywood song) (2000)
• "Crazy" (K-Ci and JoJo song) (2001)
• "Crazy" (Dream song) (2003)
• "Crazy" (Simple Plan song) (2004)
• "Crazy" (Gnarls Barkley song) (2006)
• "Crazy" (Kevin Federline song) (2006)
• "Crazy" (Snoop Dogg song) (2006)
• "Crazy" (Expatriate song) (2007)
• "Crazy" (Lumidee song) (2007)
• "(You Drive Me) Crazy" (1999), a song by Britney Spears
• "Crazy" (Pylon song) (1981)