What is the full name of the author known as J.K. Rowling?

The author known as J.K. Rowling was born Joanne Rowling.

Rowling was born on 31 July 1965 in Yate, Gloucestershire, England. Her birth name was Joanne Rowling; the middle initial in her pen name was not originally part of her given name. Her publishers wanted a name that might appeal broadly to young male readers, and Rowling adopted the initials J.K. for the Harry Potter books.

The K stands for Kathleen, the name of her paternal grandmother. Rowling has said that she did not have a middle name at birth, so Kathleen was selected when the publishing name was created. The name J.K. Rowling became internationally associated with the seven-book Harry Potter series.

A common mix-up is calling her Joanne Kathleen Rowling as though that were her original full birth name. Kathleen was added for the pen name, while Joanne is her given name. She has also published crime novels under the name Robert Galbraith.