Born into a family of artists—his father, Juan Antonio Benlliure Tomás, was a sailor, painter, and decorator, and he was the brother of the painters Blas, José, and Juan Antonio—he began his career as a self-taught sculptor. In 1881, he moved to Rome, where he lived for two decades. From there, he sent the sculpture [title missing] to the 1884 National Exhibition of Fine Arts in Madrid. damn, with which she obtained her second medal and her first public recognition. 

In 1896 he settled in Madrid, where he built a house and studio on Abascal Street. Mariano Benlliure's work is extensive and varied, encompassing all genres and techniques of sculpture.  

Throughout his life, he held public offices related to the world of culture and fine arts, such as director of the Spanish Academy in Rome (1901-1903), director general of Fine Arts (1917-1919), and director of the Museum of Modern Art in Madrid (1917-1937). He received important decorations, including the Medal of Honor at the 1900 Universal Exposition in Paris and the first Medalla de Oro of the CBA, in 1924, for his sculpture The girl, which represents his niece Matilde Benlliure and is owned by the CBA.