María Guerrero López was born into a theatre family in Madrid. She was a niece of the celebrated María Guerrero Torija whose stage name she shared. She studied at Madrid's College of Saint Louis of France and made her stage debut in September 1919, while still a child, appearing with the theatre company of her aunt and uncle. That first appearance was in :es:Campo de armiño|"Campo de armiño" by Jacinto Benavente, in which she appeared at the Teatro Odeón in Buenos Aires. Her Madrid debut followed in February 1920 at the Teatro de la Princesa, in "La Dolores" by :es:Josep Feliu i Codina|Feliu i Codina. Numerous further roles followed, in plays such as :es:La vidriera milagrosa|"La vidriera milagrosa", :es:Doña Diabla|"Doña Diabla", both by :es:Luis Fernández Ardavín|Luis Fernández Ardavín, and :es:Desdichas de la fortuna o Julianillo Valcárcel|"Desdichas de la fortuna o Julianillo Valcárcel" by the Machado brothers. In 1927 she married, as his second wife, her first cousin, Fernando Díaz de Mendoza y Guerrero. Her husband was heir to the family theatre company and by now also father, outside wedlock, of the Fernando Fernán Gómez, although he never acknowledged his paternity. He now produced three more children in his marriage with María Guerrero López. Shortly after their marriage the couples' parents died, and they took over the family theatre company, concentrating on classics such as :es:La Estrella de Sevilla|La Estrella de Sevilla and El Perro del Hortelano. They also presented several premiers including :es:La florista de la Reina|La florista de la Reina by :es:Luis Fernández Ardavín|Ardavín. Fernando Díaz de Mendoza y Guerrero was killed in 1942 when the ship on which he was travelling was sunk by a German submarine. Maria embarked on a solo career, also sometimes teaming up with :es:José Romeu Parra|José Romeu. There were notable box office successes in Madrid with productions such as :es:La hidalga limosnera|La hidalga limosnera by José María Pemán, :es:Doña María la Brava|Doña María la Brava by Eduardo Marquina, Sangre negra by :es:Guillermo Sautier Casaseca|Guillermo Sautier Casaseca and :es:Las de Caín|Las de Caín by the Quintero brothers. She had a movie career. She starred in the movie version of :es:Luis Fernández Ardavín|Ardavín's ":es:La florista de la Reina|La florista de la Reina" and later in :es:Clemente Pamplona|Clemente Pamplona's Farmacia de guardia. She also appeared in various television production including the long running :es:Novela |Novela series.
