Alejandro Fernando Amenábar Cantos (born 31 March 1972) is a Spanish film director. Amenábar was born in Santiago, Chile to a Spanish mother and Chilean father, but the family moved to Spain just one year after his birth. He studied cinema at Madrid's Universidad Complutense but eventually dropped out.

In addition to writing and directing his own films, Amenábar has maintained a notable career as a composer of film scores, including the Goya Awards-nominated score for José Luis Cuerda's La lengua de las mariposas.

Amenábar was awarded the Grand Prix of the Jury at the International Venice Film Festival in 2004 for Mar adentro ("The Sea Inside"), and in February 2005 the same film won the Academy Award for Best Foreign Language Film.

In February 2004, Amenábar came out to the Spanish gay magazine Shangay Express.

Amenábar shot in 2008 an epic film called Ágora which he wrote with Mateo Gil. The film is set in Roman Egypt and is based on the life of philosopher and mathematician Hypatia of Alexandria.