| Florimont-Claude de Mercy-Argenteau | |
| Office: | Austrian Ambassador to France |
| Term Start: | 1766 |
| Term End: | 1790 |
| Predecessor: | Georg Adam von Starhemberg |
| Successor: | Franz Paul von Blumendorf |
| Office2: | Austrian Ambassador to Russia |
| Term Start2: | 15 June 1761 |
| Term End2: | 6 October 1763 |
| Monarch2: | Maria Theresa of Austria |
| Predecessor2: | Nikolaus I, Prince Esterházy |
| Successor2: | Joseph Maria Karl von Lobkowicz |
| Office3: | Austrian Ambassador to Sardinia-Piedmont |
| Term Start3: | 14 June 1754 |
| Term End3: | 18 December 1760 |
| Monarch3: | Maria Theresa of Austria |
| Predecessor3: | Georg Barré |
| Successor3: | Johann Sigismund von Khevenhüller-Metsch |
| Birth Date: | 20 April 1727 |
| Birth Place: | Liège, Prince-Bishopric of Liege, Holy Roman Empire |
| Death Place: | London, Great Britain |
| Nationality: | Austrian |
Florimond Claude, comte de Mercy-Argenteau (20 April 1727 - 25 August 1794) was an Austrian diplomat, statesman of French noble ancestry, in the service of the Holy Roman Empire.
He was born in Liège, Prince-Bishopric of Liege, into an old noble family to Antoine Ignace Charles, Comte de Mercy-Argenteau (1692-1767), Field marshal, and his wife, Thérèse Henriette de Rouvroy de Berlus et de Pondrome (1705-1729). He entered the diplomatic service of Austria in Paris in the train of Reichsfürst Wenzel Anton of Kaunitz-Rietberg. He became Austrian ambassador in Turin at the court of King Charles Emmanuel III of Sardinia, in St. Petersburg at the court of Catherine the Great, and then Austrian ambassador in Paris at the court of King Louis XV in 1766. In Paris, his first work was to strengthen the Franco-Austrian alliance, which was cemented in 1770 by the marriage of the Dauphin, afterwards Louis XVI, with Archduchess Maria Antonia Josepha Johanna of Austria, youngest daughter of Empress Maria Theresa, afterwards known as Queen Marie Antoinette.
When Louis and Marie Antoinette ascended the throne of France in 1774, Mercy-Argenteau became one of the most powerful personages at the French court due to his influence over Marie Antoinette, which made her unpopular with the French nobility and French people. He was in Paris during the turbulent years that led up to the French Revolution, and gave powerful aid to the finance ministers Étienne Charles de Loménie de Brienne and Jacques Necker. In 1792, he became governor-general of the Austrian Netherlands, where the Brabant Revolution had just been suppressed by Austria. There, his ability and experience made him a very successful governor. Although at first in favour of moderate courses, Mercy-Argenteau supported the action of Austria in making war upon its former ally after the outbreak of the French Revolution, and in July 1794, he was appointed Austrian ambassador to Britain, but he died a few days after his arrival in London.
Florimond Claude never married, but had an extramarital affair with an opera singer from Palais Garnier, Claude Josèphe Rosalie Levasseur, Baronne de l'empire (1749-1826), daughter of Jean-Baptiste Levasseur. They had one son:[1]
After Florimond's death, Rosalie married in 1806 to André Maxime de Fouchier, Seigneur de Chanvrolles (1732-1817).[2]