Agnès Sorel (1421‑February 9, 1450), surnamed Dame de beauté, was the mistress of King Charles VII of France.

The daughter of a soldier, Jean Soreau, and of Catherine de Maignelais, Sorel was twenty years old when she was first introduced to King Charles. At that time, she was holding a position in the household of Rene I of Naples, Charles' brother-in-law. It is said that she was not only an extraordinarily beautiful young woman, but also extremely intelligent. The French king was immediately smitten by her charms and he gave her the Château de Loches as her private residence.

Soon, her presence was felt at the royal court in Chinon where her company brought the king out of a protracted depression. She had a very strong influence on the king, and that, in addition to her extravagant tastes, earned her a number of powerful enemies at court.

Agnès gave birth to three daughters: Marie de Valois, Charlotte and Jeanne de France. While pregnant with their fourth child, she joined Charles on the campaign of 1450 in Jumièges , wanting to be with him as moral support. There, she suddenly became ill and died on February 9 at the age of 28. While the cause of death was originally thought to be dysentery, scientists have now concluded that Agnès died from being poisoned by mercury. The culprit remains unknown.

Charles's son, the future King Louis XI, had been in open revolt against his father for the previous four years. It has been speculated that he poisoned Agnès in order to remove what he may have considered her undue influence over the king. It was also speculated that French financier, noble and minister Jacques Coeur poisoned her, though that theory is widely discredited as an attempt to remove Coeur from the French court.