What pseudonym did J.K. Rowling use when Harry Potter was first published?

J.K. Rowling was the pseudonym used when Harry Potter was first published.

Rowling was born Joanne Rowling and did not originally have a middle name. Her publisher, Bloomsbury, reportedly suggested using initials because of concern that some boys might avoid a book written by a woman. Rowling selected “K” in honor of her paternal grandmother, Kathleen, creating the name J.K. Rowling.

The first Harry Potter book therefore appeared under a constructed author name rather than simply Joanne Rowling. In later years, she has also used “Jo Rowling” in personal and professional contexts, but the Harry Potter novels remain globally associated with J.K. Rowling.

This naming history is often confused with her later crime-fiction identity, Robert Galbraith. Robert Galbraith was introduced for The Cuckoo’s Calling in 2013, whereas J.K. Rowling was the publishing name attached to Harry Potter and the Philosopher’s Stone in 1997.