María de las Mercedes de Borbón-Dos Sicilias y Orléans, Countess of Barcelona (Spanish: Doña María de las Mercedes Cristina Genara Isabel Luisa Carolina Victoria y Todos los Santos de Borbón-Dos Sicilias y Orléans (Spanish pronunciation: [maˈɾi.a merˈθeðes]; 23 December 1910 – 2 January 2000) was the mother of Juan Carlos I, King of Spain from 1975 to 2014.

María was born in Madrid, daughter of Prince Carlos of Bourbon-Two Sicilies, Infante of Spain, a grandson of King Ferdinand II of the Two Sicilies, and his second wife, Princess Louise of Orléans, daughter of Prince Philippe, Count of Paris, a pretender to the French throne. She was granted, at birth, the rank and precedence of an infanta of Spain, although not the actual use of the title, her own being princess of Bourbon-Two Sicilies. Her family moved to Seville, when her father was made Captain General of that province. When the Second Spanish Republic forced them into exile, they lived in Cannes and later in Paris, where she studied art at the Louvre.

On 14 January 1935, she attended the wedding, in Rome, of Infanta Beatriz of Spain, daughter of King Alfonso XIII. There she met the brother of the bride, her second cousin and future husband, the Infante Don Juan, fourth son and designated heir of Alfonso XIII of Spain. They married in Rome on 12 October 1935. When her husband took up Count of Barcelona as a title of pretence on 8 March 1941, María became the Countess of Barcelona.

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