Jeanne d Arc, known as Jeanne d Arc the 30th, is a character from the light novel and anime series Aria the Scarlet Ammo. She carries the aliases Durandal and the Diamond Dust Witch, referencing her abilities and her weapon of choice. Physically, she is depicted as a female teenager with blue eyes and gray hair that falls to her shoulders.

In her initial role within the story, Jeanne is an antagonist affiliated with a mysterious organization referred to as IU. Her primary objective is to target another character, Shirayuki, in an attempt to kidnap her and force her to join the IU. This plot leads to a confrontation where she is ultimately captured by the combined efforts of Aria, Kinji, and Shirayuki. Following her capture, her status changes significantly. As part of a plea bargain with the authorities, she is required to enroll as an exchange student at Butei High School, the main setting of the series, where she joins the second year and is placed in the Informa (intelligence) department. This transition turns her from an enemy into a more integrated character within the school environment.

Regarding her key relationships, Jeanne develops a notable friendship with Riko. The two get along well and engage in a mutually beneficial exchange of skills. Jeanne teaches Riko strategy-making techniques, while in return, she learns how to mimic people's voices from Riko.

Jeanne possesses distinct supernatural abilities. She is an ice attribute user, capable of generating and manipulating ice for combat purposes. Her primary weapon is a broadsword named Durandal, which she often covers with ice in battle. Her fighting style involves a combination of swordplay and ice-based attacks.