J.K. Rowling’s first name is Joanne.
She was born Joanne Rowling in 1965. The professional form J.K. Rowling was adopted when her publisher asked for two initials before the first Harry Potter book, even though she did not originally have a middle name. The K was chosen for Kathleen, her paternal grandmother.
Rowling is pronounced with the first name Joanne in biographies and interviews, while “J.K.” became the internationally recognized author branding for the Harry Potter books. The initials were also intended to avoid making the author’s gender immediately obvious to potential readers.
Jessica is the name of Rowling’s first daughter, which can cause confusion when people encounter both names in biographical accounts. Jessica Rowling Arantes was born in 1993; she is not the author’s first name.