The Book of Lies (full title: Which is also Falsely Called BREAKS. The Wanderings or Falsifications of the One Thought of Frater Perdurabo, which Thought is itself Untrue. Liber CCCXXXIII [Book 333]) was written by English occultist Aleister Crowley (using the pen name of Frater Perdurabo) and first published in 1912 or 1913.

The book consists of 93 chapters, each of which consists of one page of text. The chapters include a question mark, poems, rituals, instructions, and obscure allusions and cryptograms. The subject of each chapter is generally determined by its number and its corresponding qabalistic meaning. Around 1921, Crowley wrote a short commentary about each chapter, assisting the reader in the qabalistic interpretation.

Several chapters and a photograph in the book reference Leila Waddell, who Crowley called Laylah, and who, as Crowley's influential Scarlet Woman, acted as his muse during the writing process of this volume.