What middle name was added to J.K. Rowling’s author name?

The middle name added to J.K. Rowling’s author name was Kathleen.

Rowling was born Joanne Rowling, but her publisher requested a name using initials before Harry Potter and the Philosopher’s Stone was published. The resulting name, J.K. Rowling, was intended to avoid making the author’s gender obvious to potential readers.

Kathleen was selected in honor of Rowling’s paternal grandmother. It supplied the “K” in the pen name, even though Kathleen was not part of Rowling’s birth name. The author is therefore commonly called J.K. Rowling rather than Joanne Kathleen Rowling in bibliographic and media references.

This detail is often mixed up with Rowling’s later use of the name Robert Galbraith. Galbraith was a separate pseudonym for her crime novels, while J.K. Rowling remained the name associated with Harry Potter and several other works.