What is the middle initial in J.K. Rowling’s pen name short for?

The K in J.K. Rowling’s pen name stands for Kathleen.

Rowling was born Joanne Rowling and did not originally have a middle name. When Bloomsbury prepared to publish Harry Potter and the Philosopher’s Stone, the publisher believed a name with initials might appeal broadly to readers and did not want to use a clearly female first name on the cover. Rowling chose K in honour of her paternal grandmother, Kathleen Ada Bulgen.

The initials became one of the most recognizable author names in modern publishing. Rowling continued to use “J.K. Rowling” professionally even though her birth name was Joanne Rowling. The name is therefore not a shortened form of a legal middle name.

The author’s name is also sometimes written incorrectly as “J.K. Rolling.” The correct spelling is Rowling, with “Rowling” derived from her family name. Her later crime novels used Robert Galbraith instead of the initials.