腓特烈二世（德語：Friedrich II von Preußen, der Große，1712年1月24日－1786年8月17日），史稱腓特烈大帝。普魯士國王（1740年5月31日-1786年8月17日在位），軍事家，政治家，作家,作曲家。統治時期普魯士軍力大規模發展，領土大舉擴張，文化藝術得到贊助和支持，「德意志啟蒙運動」得以開展。其使普魯士在歐洲大陸取得大國地位，並在德意志內部取得霸權，向以普魯士為中心武力統一德意志的道路邁出第一步。腓特烈二世是歐洲歷史上最偉大的名將之一，也是歐洲「開明專制」君主的代表人物，並且為啟蒙運動時期的文化名人，在政治、經濟、哲學、法律、甚至音樂諸多方面都頗有建樹，為啟蒙運動一大重要人物。
Frederick II (German: Friedrich; 24 January 1712 – 17 August 1786) was the thirdHohenzollern king, reigning over the Kingdom of Prussia from 1740 until 1786.Frederick's achievements during his reign included his military victories, his reorganization of Prussian armies, his patronage of the Arts and the Enlightenment in Prussia, and his final success against great odds in the Seven Years' War. He became known asFrederick the Great (Friedrich der Große) and was nicknamed Der Alte Fritz ("OldFritz") by the Prussian people.
In his youth, Frederick was more interested in music and philosophy than the art of war. He defied his authoritarian father, Frederick William I, and sought to run away with his best friend Hans Hermann von Katte. They were caught at the border and King Frederick William I nearly executed his son for desertion. After being pardoned, he was forced to watch the official beheading of Hans. Upon ascending to the Prussian throne, he attackedAustria and claimed Silesia during the Silesian Wars, winning military acclaim for himself and Prussia. Near the end of his life, Frederick physically connected most of his realm by conquering Polish territories in the First Partition of Poland. He was an influential military theorist whose analysis emerged from his extensive personal battlefield experience and covered issues of strategy, tactics, mobility and logistics.
Frederick was a proponent of enlightened absolutism. He modernized the Prussian bureaucracy and civil service and pursued religious policies throughout his realm that ranged from tolerance to segregation. He reformed the judicial system and made it possible for men not of noble stock to become judges and senior bureaucrats; he also encouraged immigrants of various nationalities to come to Prussia. Some critics, however, point out his oppressive measures against conquered Polish subjects. Frederick supported arts and philosophers he favored, but at the same time enacted several laws censoring the press. Frederick is buried at his favorite residence, Sanssouci in Potsdam. Because he died childless, Frederick was succeeded by his nephew, Frederick William II, son of his brother, Augustus William.
Nearly all 19th century German historians made Frederick into a romantic model of a glorified warrior, praising his leadership, administrative efficiency, devotion to duty and success in building up Prussia to a leading role in Europe. Historian Leopold von Rankewas unstinting in his praise of Frederick's "Heroic life, inspired by great ideas, filled with feats of arms...immortalized by the raising of the Prussian state to the rank of a power."Johann Gustav Droysen was even more extolling. Frederick remained an admired historical figure through the German Empire's crushing defeat in First World War, and the Nazis glorified him as a great German leader pre-figuring Hitler, but his reputation became far less favorable in 1945 in both East and West Germany after the fall of the Nazi regime, largely due to his status as a favorite icon of the Nazis.