J.K. Rowling’s first name is Joanne. She was born Joanne Rowling on 31 July 1965 in Yate, Gloucestershire, England.
The “K” in her pen name does not represent a second given name. Rowling adopted it at her publisher’s suggestion, because the publisher believed that a name with two initials might appeal broadly to readers. The K was taken from Kathleen, the first name of her paternal grandmother.
Before the Harry Potter books became famous, Rowling generally used Joanne Rowling. The author has also explained that she prefers to be called Jo. A common mistake is to assume that “J.K.” is a full traditional double initial; it is instead a shortened publishing name built from Joanne and Kathleen.
Her pen name is written with periods in many references, although publishing styles sometimes omit them.