Harry Potter’s birthday in J.K. Rowling’s books is 31 July.
Harry was born on 31 July 1980, according to the series’ chronology. The date is also J.K. Rowling’s birthday, creating a deliberate connection between the author and her most famous character.
Harry’s birthday is mentioned repeatedly throughout the novels. In Harry Potter and the Philosopher’s Stone, he discovers that Hagrid has brought him a birthday cake when he is living with the Dursleys. Later stories use the date to mark changes in Harry’s age and circumstances.
The date is sometimes confused with other important wizarding-calendar dates. Hogwarts students generally return to school on 1 September, while Halloween is associated with several major events. Harry’s birthday, however, is 31 July, and this detail remains consistent across the main book series.