|This article is non-canon.
This article covers a subject that has been deemed non-canon by either the author or the Harry Potter licensees, and thus should not be taken as a part of the "real" Harry Potter universe.
Sheffield is a city and metropolitan borough of South Yorkshire, England. During one of Marge Dursley's visits to Privet Drive, Harry Potter lost control of his magic, causing her to inflate like a balloon. Some hours after the Inflated Marge went out a door at Privet Drive, the Accidental Magic Reversal Squad found her circling a chimney in Sheffield. She was then punctured and her memory modified.
- Harry Potter and the Prisoner of Azkaban (film) (Mentioned only)