J.K. Rowling’s first name, as given in her published name, is Joanne.
She was born Joanne Rowling in Yate, Gloucestershire, England, on 31 July 1965. The initial “K” was added for her publishing name rather than representing a middle name given at birth. Her publishers wanted a name that might appeal broadly to young readers, and Rowling chose “K” in honor of her paternal grandmother, Kathleen.
Rowling became widely known through the Harry Potter novels, whose author credit appears as “J. K. Rowling.” The initials sometimes lead readers to assume that her full name is Joanne Kathleen Rowling, but “Kathleen” was adopted for the pen name and was not part of her original birth name.
She has also published fiction under the name Robert Galbraith. That pseudonym is associated with her crime novels, beginning with The Cuckoo’s Calling in 2013. “Joanne” remains the first name connected with her biography and legal identity.