The Kaunitz family (Kounicové) belonged to an ancient Czech nobility and, like the related Martinic dynasty, derived its lineage from the medieval Vršovci clan in the Kingdom of Bohemia.

Elevated to the hereditary rank of a Count (Graf) in 1683, his diplomacy contributed to the 1686 League of Augsburg against King Louis XIV of France and the 1697 Treaty of Ryswick that ended the Nine Years' War.

Wenzel Anton's father, Count Maximilian Ulrich, was appointed a member of the Aulic Council (Reichshofrat) in 1706; he served as Imperial envoy and as governor (Landeshauptmann) of Moravia from 1720.

Wenzel Anton's granddaughter Eleonora (daughter of his eldest son, Ernest) married a successor in the office of State Chancellor, Prince Klemens von Metternich.

He became a chamberlain of the Habsburg emperor Charles VI, and continued his education for some years by a Grand Tour to Berlin, the Netherlands, Italy, Paris, and England.

Extremely displeased with the provisions that deprived Austria of the provinces of Silesia and Glatz and guaranteed them to the warlike King of Prussia, he reluctantly signed the resulting Treaty of Aix-la-Chapelle on 23 October 1748.

Kaunitz's most important and influential office was that of State Chancellor and minister of foreign affairs, which he held from 1753 to 1792 and where he had Empress Maria Theresa's full trust—against the opposition of her husband, Francis Stephen.

Thanks in large part to him, Habsburg Austria established itself as a sovereign great power, entering into the Treaty of Versailles (1756) with her old enemy, the French ancien régime, commonly known as Diplomatic Revolution (renversement des alliances).

Upon the outbreak of the French and Indian War overseas in 1754, he had the Austrian ambassador in Paris, Prince Georg Adam of Starhemberg, raise the topic of forming a defensive league.

On 29 August 1756, King Frederick's Prussian Army invaded the Electorate of Saxony in a preemptive strike; they rolled over the Saxon forces and occupied Dresden.

From about 1760, gradual exhaustion of all forces became obvious, and Kaunitz reacted by depriving his long-time foe Court Chancellor Count Friedrich Wilhelm von Haugwitz of his powers.

He worked towards the goal of subjecting the Catholic Church to the state, most notably against tax exemption and the traditional institution of mortmain ownership of real estates.

When the Austrian position became untenable, Kaunitz carried the peace negotiations on his own initiative; by the 1779 Treaty of Teschen, he won the Bavarian Innviertel region for Austria.

In Imperial matters, he was able to dominate the Perpetual Diet of Regensburg; in 1780 he was also successful in placing the Habsburg Archduke Maximilian Francis of Austria, Joseph's younger brother, as a coadjutor bishop in the Electorate of Cologne and the Prince-Bishopric of Münster.

Kaunitz died in 1794 at his city palace in Vienna and was buried in his family vault beneath the Chapel of St. John the Baptist in Slavkov cemetery.