The Alcázar of Seville (Spanish: Real Alcázar de Sevilla) is a fortified palace (alcázar) built in Seville by the Umayyads of Spain and modified several times during and after the Muslim period. It is considered the finest example of Mudéjar architecture on the Iberian Peninsula. The Spanish royal family still used the upper floor until recently, but now prefers the Hotel Alfonso XIII next door. To indicate their presence, the flag at the tourist entrance is lowered.

The Palacio Alto, the palace located in the upper part of the Mudéjar palace complex, is a National Heritage Site. It includes a vestibule built during the time of the Catholic Monarchs, the Oratory of the Catholic Monarchs, the Reception Dining Hall, built during the reign of Philip II, and the Belvedere of the Catholic Monarchs, built after 1492, where One can appreciate the influence of Granada in the bedroom of King Don Pedro, in the 14th-century Mudéjar palace, and in the official audience hall. Tours are managed by the Patronato del Real Alcázar de Sevilla.

In 1526, the marriage of Charles V (Charles I of Spain) and his cousin Isabel of Portugal, daughter of King Manuel I the Fortunate, was celebrated at the Alcázar. Their marriage was a marriage of convenience, encouraged by the Cortes of Castile, and ultimately blossomed into a love match. The emperor did not remarry after his wife's death in 1539.