Which Harry Potter novel by J.K. Rowling sold the most copies in its first 24 hours in the United States?

Harry Potter and the Deathly Hallows set the first-day U.S. sales record for a book, selling about 8.3 million copies in its first 24 hours. J.K. Rowling’s seventh Harry Potter novel was released on 21 July 2007.

The launch followed years of intense anticipation because it was marketed as the final novel in the main series. In the United States, Scholastic organized a large coordinated release involving bookstores, midnight events, and extensive advance reservations. The book’s initial sales exceeded the first-day totals of the previous Harry Potter releases.

The title is sometimes confused with Harry Potter and the Half-Blood Prince, which had previously set a major first-day sales record. Deathly Hallows surpassed that performance. Its story follows Harry, Ron, and Hermione as they search for Horcruxes instead of returning to a normal Hogwarts school year.