J.K. Rowling’s first given name is Joanne.
She was born Joanne Rowling on 31 July 1965 in Yate, Gloucestershire, England. The “K” in her professional name does not represent a second given name originally given to her at birth. Rowling adopted Kathleen as a pen-name middle initial in honor of her paternal grandmother when preparing to publish Harry Potter.
Her publisher encouraged the use of initials because of concern that young male readers might be less likely to choose a fantasy novel written by a woman. Rowling therefore became known worldwide as J.K. Rowling rather than simply Joanne Rowling.
The name Joanne remains important in biographical references, while “J.K. Rowling” is the author name printed on the Harry Potter books. She has also published crime fiction under the separate pen name Robert Galbraith.