J.K. Rowling’s first name is Joanne.
She was born Joanne Rowling on 31 July 1965 in Yate, Gloucestershire, England. The initials in her pen name do not represent a conventional two-part given name: Rowling has no middle name.
Bloomsbury asked her to use initials for the Harry Potter books because the publisher believed that a gender-neutral author name might appeal more broadly to young readers. She added the K from Kathleen, her paternal grandmother’s name.
The author is also known as Robert Galbraith, the pseudonym used for her crime novels. That name is separate from the initials used for her fantasy fiction and nonfiction writing.