J.K. Rowling’s first name, as given in her full 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 middle name: Rowling has said the “K” was added for her publisher and stands for Kathleen, her paternal grandmother’s name.
Rowling generally became known publicly as J.K. Rowling rather than by her full name. The name helped create a gender-neutral author identity for the Harry Potter books, whose publisher believed that young male readers might be less likely to choose a book by a woman author.
A common mix-up is assuming that the “K” was part of Rowling’s birth name. It was not. Rowling’s full name is Joanne Rowling, and she later used the married name Joanne Murray for a period before becoming internationally known by her pen name.