Alucarda (Spanish: Alucarda, la hija de las tinieblas, or Alucarda, the daughter of darkness) is a 1977 Mexican supernatural horror film directed by Juan López Moctezuma, and starring Tina Romero, Claudio Brook, Susana Kamini, and David Silva. A loose adaptation of Carmilla (1872), it revolves around two teenage orphan girls living in a Catholic convent, who unleash a demonic force and become possessed. Since its release, "Alucarda" has achieved cult status.

A Mexican production, the film was shot in English and completed in 1975. It premiered at the 1977 Paris Fantastic Film Festival, and had a brief Mexican theatrical release in a censored version. It was released theatrically in France on 26 December 1977. Though not well-received in Mexico, it received some acclaim internationally.

The film was released under several alternate titles on home video in English-speaking countries, including Innocents from Hell and Sisters of Satan. The film has been noted by film scholars for its themes regarding national tradition versus modernity, as well as the tensions between science and religion, and the failures of both. Because of its depiction of nuns in emotionally-heightened, supernatural situations, the film has been associated with the nunsploitation genre. It is also widely regarded as one of the best Mexican horror films of all time.