J.K. Rowling’s first name is Joanne.
She was born Joanne Rowling on 31 July 1965. The initial J in her public author name represents Joanne, while the K was added in honour of her paternal grandmother, Kathleen Ada Bulgen. Rowling has said that she did not have a middle name at birth, so the K was selected for the publishing name.
Her publisher reportedly believed that a gender-neutral author name might appeal more broadly to boys, leading to the initials J.K. Rowling. She has continued to use Joanne Rowling in personal and professional contexts, while J.K. Rowling became the name most closely associated with Harry Potter. The name should not be confused with her later crime-fiction pseudonym, which is a separate author identity.