J.K. Rowling’s first name is Joanne.
She was born Joanne Rowling on 31 July 1965 in Yate, Gloucestershire, England. Her published name became J.K. Rowling rather than Joanne Rowling after her publisher requested a name that did not clearly identify the author as a woman. Rowling had no middle name at birth, so she selected Kathleen, her paternal grandmother’s name, for the initials.
The “K” in J.K. Rowling therefore stands for Kathleen, while the “J” stands for Joanne. She has also used the pen name Robert Galbraith for her crime novels. These different names belong to the same author but are associated with different areas of her writing career.
Rowling has sometimes been called Jo by people close to her, but Joanne is the formal first name relevant to her biography. “Joanne” should not be confused with “Joan” or “Joanna,” which are separate names and are not the answer to this biographical question.