Metternich's coat of arms
Klemens Metternich was born into the House of Metternich on 15 May 1773 to Franz George Karl Count Metternich-Winneburg zu Beilstein, a diplomat who had passed from the service of the Archbishopric of Trier to that of the Imperial court, and his wife Countess Maria Beatrice Aloisia von Kageneck. He was named in honour of Prince Clemens Wenceslaus of Saxony, the archbishop-elector of Trier and the past employer of his father. He was the eldest son and had one older sister. At the time of his birth the family possessed a ruined keep at Beilstein, a castle at Winneberg, an estate west of Koblenz, and another in Königswart, Bohemia, won during the 17th century. At this time Metternich's father, described as "a boring babbler and chronic liar" by a contemporary, was the Austrian ambassador to the courts of the three Rhenish electors (Trier, Cologne and Mainz). Metternich's education was handled by his mother, heavily influenced by their proximity to France; Metternich spoke French better than German. As a child he went on official visits with his father and, under the direction of Protestant tutor John Frederick Simon, was tutored in academic subjects, swimming, and horsemanship.<
In the summer of 1788 Metternich began studying law at the University of Strasbourg, matriculating on 12 November. While a student he was for some time accommodated by Prince Maximilian of Zweibrücken, the future King of Bavaria. At this time he was described by Simon as "happy, handsome and lovable", though contemporaries would later recount how he had been a liar and a braggart. Metternich left Strasbourg in September 1790 to attend Leopold II's October coronation in Frankfurt, where he performed the largely honorific role of Ceremonial Marshall to the Catholic Bench of the College of the Counts of Westphalia. There, under the wing of his father, he met with the future Francis II and looked at ease among the attendant nobility.
Between the end of 1790 and summer of 1792 Metternich studied law at the University of Mainz, receiving a more conservative education than at Strasbourg, a city the return to which was now unsafe. In the summers he worked with his father, who had been appointed plenipotentiary and effective ruler of the Austrian Netherlands. In March 1792 Francis succeeded as Holy Roman Emperor and was crowned in July, affording Metternich a reprisal of his earlier role of Ceremonial Marshall. In the meantime France had declared war on Austria, beginning the War of the First Coalition (1792–7) and making Metternich's further study in Mainz impossible. Now in the employment of his father, he was sent on a special mission to the front. Here he led the interrogation of the French Minister of War the Marquis de Beurnonville and several accompanying National Convention commissioners. Metternich observed the siege and fall of Valenciennes, later looking back on these as substantial lessons about warfare. In early 1794 he was sent to England, ostensibly on official business helping Viscount Desandrouin, by the Treasurer-General of the Austrian Netherlands, to negotiate a loan.