Queen Sofía of Spain (Spanish: Su Majestad la Reina Sofía de España, Greek: Βασίλισσα Σοφία της Ισπανίας;) born Princess Sophia of Greece and Denmark on November 2, 1938; full name Sophía Margaríta Viktoría Frederíki), is the Queen Consort of King Juan Carlos I of Spain. Princess Sophia of Greece and Denmark was born in Athens, Greece on November 2, 1938, the eldest child of the King Paul I of the Hellenes (1901-1964) and his wife, Queen Frederika (1917-1981), a former princess of Hanover. Queen Sofia is a member of the Schleswig-Holstein-Sonderburg-Glücksburg dynasty. Her brother is Constantine II of Greece and her sister Princess Irene of Greece and Denmark. However, since the restoration of democracy, the royal titles are not recognized in Greece, where the former royal family is held in low regard by most Greeks.

Princess Sophia spent her childhood in Egypt and South Africa during her family's exile from Greece during World War II. They returned to Greece in 1946. She finished her education at the prestigious Schloss Salem boarding school in Southern Germany, and then studied pediatrics, music, and archeology in Athens. On May 14, 1962 Princess Sophia of Greece and Denmark married Prince Juan Carlos of Spain, the future king, whom she met on a cruise of the Greek Islands in 1954. In doing so, she relinquished her rights to the throne of Greece and converted to Roman Catholicism from Greek Orthodoxy. Further, the Latin transliteration of her Greek name Σοφία was changed from Sophia to the Spanish variant Sofía, which nonetheless is pronounced