(The) Sleep of Reason may refer to:
Sleep of Reason (album), a 2013 album by Raffertie Sleep of Reason, a 2005 album by The Eternal The Sleep of Reason (Day novel), a novel by Martin Day based on the television series Doctor Who The Sleep of Reason (Snow novel), the tenth book in C. P. Snow's Strangers and Brothers series The Sleep of Reason, a 2014 horror anthology edited by Spike Trotman
See also The Sleep of Reason Produces Monsters, an etching by Francisco Goya