The Royal Standard of Spain is the official flag of the King of Spain. It comprises a crimson square, traditional colour of both Castilian and Spanish monarchs, with the coat of arms of the King in the center. It is raised over the official royal residence in Madrid, the Palacio de la Zarzuela and other Spanish royal sites, when the monarch is in residence and displayed on his official car as small flag. The current flag was adopted when Felipe VI acceded the throne as King of Spain on 19 June 2014. The Royal Standard is regulated by Rule 2 of Royal Decree 527/2014, 20 June, an amendment to Title II of Spanish Royal Decree 1511/1977 adopting Flags, Standards, Guidons, Insignia and Emblems Regulation.

In heraldry and vexillology, a heraldic flag is a flag containing coats of arms, heraldic badges, or other devices used for personal identification.