Ewald Friedrich Graf von Hertzberg (2 September 1725 – May 22, 1795) was a Prussian statesman.
Hertzberg, who came of a noble family which had been settled in Pomerania since the 13th century, was born at Lottin (present-day Lotyń, a part of Okonek) near Neustettin.
After 1739 he studied, chiefly classics and history at the gymnasium at Stettin, and in 1742 entered the university of Halle as a student of jurisprudence, becoming in due course a doctor of laws in 1745. In addition to this principal study, he was also interested while at the university in historical and philosophical (Christian Wolff) studies. A first thesis for his doctorate, entitled Jus publicum Brandenburgicum, was not printed, because it contained a criticism of the existing condition of the state. Shortly afterwards Hertzberg entered the government service, in which he was first employed in the department of the state archives (of which he became director in 1750), soon after in the foreign office, and finally in 1763 as chief minister (Cabinetsminister). In 1752 he married Baroness Marie von Knyphausen, a marriage which was happy, but childless.
For more than forty years Hertzberg played an active part in the Prussian foreign office. In this capacity he had a decisive influence on Prussian policy, both under Frederick the Great and Frederick William II. At the beginning of the Seven Years' War (1756) he took part as a political writer in the Hohenzollern-Habsburg quarrel, both in his Ursachen, die S.K.M. in Preussen bewogen haben, sich wider die Absichten des Wienerischen Hofes zu setzen and deren Ausführung zuvorzukommen ("Motives which have induced the king of Prussia to oppose the intentions of the court of Vienna, and to prevent them from being carried into effect"), and in his Mémoire raisonné sur la conduite des tours de Vienne et de Saxe, based on the secret papers taken by Frederick the Great from the archives of Dresden.