Fleur Isabelle Delacour is a student of Beauxbatons Academy in France, and is selected as a champion in the prestigious Triwizard Tournament. Her father is a Frenchman who is unnamed but described in the books as being round and having a short black beard; her mother, Apolline Delacour, is the daughter of a Veela, from whom Fleur and her younger sister, Gabrielle, inherited their silvery-blonde hair, pale eyes, good looks, and ability to entrance men. According to Rowling, Fleur's name comes from the French phrase fleur de la coeur, meaning, "flower of the heart".

During the Triwizard Tournament, Fleur is initially aloof and unfriendly. During the second task of the Tournament, she attempts to rescue her sister from the lake, but fails. When Harry rescues Gabrielle instead, Fleur becomes much warmer towards both Harry and Hogwarts in general. Fleur takes last place in the Triwizard Tournament, due to disguised Death Eater Barty Crouch Jr stunning her when she passes by the area of the maze that he is watching. She later takes a job at Gringotts, and it is here that she meets Bill, to whom she later becomes engaged, to the initial dismay of Mrs Weasley and Ginny. Bill is attacked by werewolf Fenrir Greyback near the end of Harry Potter and the Half-Blood Prince. However, since Greyback is in his human form at the time of the attack, Bill suffers only partial lycanthropy contamination. The wedding plans, however, remained unchanged; this attitude earns her a lot of respect from Bill's otherwise disapproving family.

In Harry Potter and the Deathly Hallows, Fleur and Bill take part in the operation to escort Harry safely to The Burrow, and they witness Mad-Eye Moody being killed by Voldemort himself. The couple have their wedding at the Burrow, but the event is interrupted when Death Eaters attack at the wedding reception after the fall of the Ministry of Magic. The newlyweds later provide a safe haven for the trio and some others in Shell Cottage, their home, after the refugees narrowly escape Malfoy Manor. Both Bill and Fleur are combatants for the Order during the Battle of Hogwarts, and survive the battle. The couple have three children: Victoire, Dominique and Louis