María Eugenia Martínez de Irujo y Fitz-James Stuart, 12th Duchess of Montoro, GE (born 26 November 1968) is a Spanish aristocrat and socialite.

Born in Madrid, she is the youngest and only daughter of Luis Martínez de Irujo y Artázcoz and Cayetana Fitz-James Stuart, 18th Duchess of Alba.

Her official seat of residence is at Liria Palace in Madrid, but she also spends time at her property La Pizana in Gerena, in the province of Sevilla.

On October 23, 1998, the Duchess married Francisco Rivera Ordóñez at Seville Cathedral.

The couple divorced in 2002, and had a daughter: On November 17, 2017, the Duchess married Narcís Rebollo Melció, president of Universal Music Spain and Portugal.