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 author name do not originally represent two given names: the “J” stands for Joanne, while the “K” was added for publication and represents Kathleen, her paternal grandmother’s name.
Rowling has explained that Bloomsbury wanted a gender-neutral author name because publishers feared that some boys might avoid a book written by a woman. She therefore published the Harry Potter books as J.K. Rowling rather than using her full name.
A common mix-up is assuming that “K” is part of the name she received at birth. Joanne Kathleen Rowling is the expanded form associated with her pen name, while “Jo” is also a familiar short form used in accounts of her early life.