The Phantom of the Opera (French: Le Fantôme de l'Opéra) is a novel by French author Gaston Leroux. It was first published as a serial in Le Gaulois from 23 September 1909 to 8 January 1910, and was released in volume form in late March 1910 by Pierre Lafitte. The novel is partly inspired by historical events at the Paris Opera during the nineteenth century, and by an apocryphal tale concerning the use of a former ballet pupil's skeleton in Carl Maria von Weber's 1841 production of Der Freischütz. It has been successfully adapted into various stage and film adaptations, most notable of which are the 1925 film depiction featuring Lon Chaney, and Andrew Lloyd Webber's 1986 musical.

The Phantom of the Opera is a riveting story that revolves around the young, Swedish Christine Daaé. Her father, a famous musician, dies, and she is raised in the Paris Opera House with his dying promise of a protective angel of music to guide her. After a time at the opera house, she begins hearing a voice, who eventually teaches her how to sing beautifully. All goes well until Christine's childhood friend Raoul comes to visit his parents, who are patrons of the opera, and he sees Christine when she begins successfully singing on the stage. The voice, who is the deformed, murderous 'ghost' of the opera house named Erik, however, grows violent in his terrible jealousy, until Christine suddenly disappears. The phantom is in love, but it can only spell disaster.