Peter III Fiodorovich (1728- 1762), or Karl Peter Ulrich before his conversion to Russian Orthodoxy, was Emperor of Russia for six months within 1761-62. His parents were Duke Karl Friedrich of Holstein-Gottorp (nephew of Charles XII of Sweden) and Anna Petrovna (1708-1728), a daughter of Emperor Peter the Great of Russia and his second wife, Catherine I of Russia. He was the first of the Romanov-Holstein-Gottorp line which ruled Russia until 1917. In 1745, Empress Elizabeth Petrovna arranged Peter’s marriage with Sophia Augusta Frederica of Anhalt-Zerbst (later Catherine the Great), by whom he had two children: Paul (1754-1801), later Emperor Paul I of Russia, and Anna (1757-59). As a result of the 1726 palace coup led by his wife, Peter III was dethroned and assassinated.

During the short reign of Peter III, Tsarskoe Selo underwent no significant changes.