Harry Potter’s birthday is 31 July, the same date as J.K. Rowling’s birthday. Rowling was born on 31 July 1965, while Harry is born on 31 July 1980 in the fictional chronology of the novels.
The shared date is a well-known connection between author and character, but it does not mean Harry is a self-portrait. Rowling has described Harry as a fictional character whose experiences and personality developed independently within the story.
Harry’s birth date matters in the plot because it helps establish his age when he receives his Hogwarts letter and begins each school year. The books generally place the start of term on 1 September, so Harry is already a year older by the time he arrives for a new academic year.
Fans sometimes confuse Harry’s birthday with Hermione Granger’s, which is 19 September, or with the Hogwarts start date. The precise date is 31 July for both Harry and Rowling.