Phantom is a 1990 novel by Susan Kay, based on the 1910 Gaston Leroux novel The Phantom of the Opera. It is a biography of the title character Erik.

Erik is the title character from Gaston Leroux's 1910 novel Le Fantôme de l'Opéra, best known to English speakers as The Phantom of the Opera. The character has been adapted to alternative media several times, including in the 1925 film adaptation starring Lon Chaney, the 1943 remake starring Claude Rains, the 1962 remake starring Herbert Lom, and Andrew Lloyd Webber's 1986 musical.