Madame DuBarry, whose given name is Jeanne Bécu, is the last official mistress of King Louis XV in the anime La Rose de Versailles. She is a woman of average height with a slender figure, blonde hair, and bluish-green eyes, often depicted with an expression of anger or a scheming smirk. Her background is one of humble origins; she was born into poverty and worked her way up through society, eventually catching the attention of Count du Barry and marrying him to become Countess du Barry. However, it is said that she quickly poisoned her new husband and used her new resources to enter Versailles, where she became the mistress of the aging king.

In terms of personality, Madame DuBarry is ambitious, manipulative, and cunning, driven by a desire for power, status, and security. She is acutely aware of her precarious position at court due to her low birth and works tirelessly to maintain her influence over the king and to be accepted by the nobility. Her motivations are largely self-serving: she seeks to solidify her place at Versailles, secure her future, and protect herself from the scorn of the aristocracy, particularly from the young Dauphine Marie Antoinette, who refuses to speak to her out of contempt.

Her role in the story is that of a primary antagonist to Marie Antoinette and a source of conflict within the court. She is constantly plotting against the Dauphine and the protagonist Oscar François de Jarjayes, using her influence over Louis XV to undermine her rivals. After King Louis XV contracts smallpox, he is forced by the bishop to remove her from his side as a sin before his death. Following the king's death, Madame DuBarry is forcibly removed from Versailles and sent to a convent, marking her fall from power. In one memorable scene in the anime, she is forced to change into ragged clothes and is whipped by soldiers, only to be rescued by her bodyguard, Oscar.

Her key relationships are defined by her rivalry with Marie Antoinette, who despises her for her low origins and her hold over the king, and her reliance on the king for protection and status. She also has a complex dynamic with Oscar, who serves as the head of the Royal Guard and is loyal to the Dauphine, though Oscar at one point saves her from humiliation. Her development is limited, as she remains a largely static figure driven by her ambition and fear of losing her position, but her eventual exile and disgrace mark a significant turn in her fortunes. Her notable abilities lie in her political maneuvering and her skill at court intrigue, using her charm and cunning to influence events behind the scenes, even though she has little direct power beyond her relationship with the king. She serves as a foil to the more principled characters, embodying the corruption and moral decay of the ancien régime.