He was the first child of Arthur and Molly Weasley (née Prewett) and the eldest brother of Charile, Percy, George, Fred, Ron, and Ginny. He attended Hogwarts School of Witchcraft and Wizardry from September 1982 to June 1989, and was both a prefect and Head Boy. After graduating, he went to work for Gringotts Wizarding Bank as a Curse Breaker, working in Egypt. In 1995, he returned to England and joined the reconstituted Order of the Phoenix to face the reborn Lord Voldemort. During this time, he started dating Fleur Delacour, and eventually asked her to marry him after a year of seeing each other.
Bill met Fleur Delacour in June 1995, when he accompanied his mother to Hogwarts to support Harry Potter during the Third Task of the Triwizard Tournament, in which she was also a Champion. Fleur was attracted to him immediately, eyeing him from a distance. Shortly after, Bill moved back to England to work for the Order of the Phoenix, taking a desk job at Gringotts. Fleur had taken a part-time job at the bank to improve her English, and the two began dating shortly after. After a year together, Bill proposed, and Fleur accepted. His mother felt it was too soon for him to get married and worried that he was only doing it in response to the return of Lord Voldemort. In addition, Fleur's blunt attitude and tendency to speak her mind irritated both Molly and Ginny. Mrs. Weasley became convinced that their feelings for each other were based on physical attraction, and the adventurous side of each other - him as a Curse Breaker, and her as a Triwizard Champion. Following Bill's scarring during the Battle of the Astronomy Tower, Fleur showed her feelings for Bill by declaring that she still loved him no matter what he looked like, and her insistence that she would take care of his injuries. Her declaration convinced Mrs. Weasley that her son had made the right choice, and the two women finally put aside their differences. Bill and Fleur married on 1 August 1997, and set up a home of their own, Shell Cottage. Their union produced three children: Victoire, Dominique, and Louis.
Bill is portrayed by English actor Richard Fish and Irish actor Domhnall Gleeson, in the film adaptation of Harry Potter.