| The Marquis of Vergennes | |
| Office1: | French Ambassador to Switzerland |
| Term Start1: | 1775/1786 |
| Term End1: | 1777/1789 |
| Office2: | French Ambassador to Portugal |
| Term Start2: | 1777 |
| Term End2: | 1779 |
| Office3: | French Ambassador to the Republic of Venice |
| Term Start3: | 1779 |
| Term End3: | 1785 |
| Office4: | President of the Court of Auditors of Burgundy |
| Monarch4: | King Louis XV of France |
| Birth Date: | 4 November 1718 |
| Birth Place: | Dijon, France |
| Death Place: | Paris, Revolutionary France |
| Children: | Five |
| Nationality: | French |
Jean-Charles Gravier, Marquis of Vergennes[1] and Baron of Tenare, was a French aristocrat, magistrate and diplomat. He was the elder brother of the French Minister of Foreign Affairs and Louis XVI's Chief Minister, Charles Gravier de Vergennes.
Born in Dijon in 1718, the eldest son of Charles Gravier, Lord of Vergennes, he became a chief counselor in the Court of Auditors of Burgundy in 1738 and then President of the Court in 1742. As the eldest son, he inherited his family's estates. He was named as the French King's ambassador in Switzerland from 1775 to 1777. As ambassador, he renewed the treaty of alliance between France and the Swiss cantons on 28 May 1777, in Solothurn. He was then appointed as French Ambassador to Portugal in 1777, as Ambassador to the Republic of Venice from 1779 to 1785, and as Ambassador, for a second time, to Switzerland from 1786 to 1789.
Imprisoned in the Saint-Lazare Prison during the French Revolution, he was guillotined alongside his eldest son Charles Gravier de Vergennes on 24 July 1794, in Paris.
Jean Gravier married to Jeanne Chevignard de Chavigny from a noble Burgundian family related to the Graviers, daughter of Philibert Chevignard de Chavigny, President of the Parliament of Besançon and niece of the ambassador Théodore Chevignard de Chavigny, Count of Toulongeon. He is the grand-father of Claire Élisabeth de Vergennes, Madame de Rémusat and of the politician, anti-revolutionary fighter and Marshal of France, Antoine-Charles de Ganay, among others. The Gravier family is a family of the surviving French nobility.