Sophia of Prussia (Sophie Dorothea Ulrike Alice, Greek: Σοφία Δωροθέα Ουλρίκη Αλίκη, romanized: Sofía Dorothéa Oulríki Alíki; 14 June 1870 – 13 January 1932) was Queen of Greece from 18 March 1913 to 11 June 1917 and again from 19 December 1920 to 27 September 1922 as the wife of King Constantine I.
A member of the House of Hohenzollern and child of Frederick III, German Emperor, Sophia received a liberal and Anglophile education, under the supervision of her mother Victoria, Princess Royal. In 1889, less than a year after the death of her father, she married her third cousin Constantine, heir apparent to the Greek throne. After a difficult period of adaptation in her new country, Sophia gave birth to six children and became involved in the assistance to the poor, following in the footsteps of her mother-in-law, Queen Olga. However, it was during the wars which Greece faced during the end of the 19th and the beginning of the 20th century that Sophia showed the most social activity: she founded field hospitals, oversaw the training of Greek nurses, and treated wounded soldiers.