What is the “K” in J.K. Rowling’s pen name short for?

The “K” in J.K. Rowling’s pen name stands for Kathleen. Rowling’s birth name was Joanne Rowling, and Kathleen was her paternal grandmother’s name.

Bloomsbury asked Rowling to use initials rather than her full first name when Harry Potter and the Philosopher’s Stone was published in Britain in 1997. The publisher believed that young male readers might be less likely to choose a book written by a woman. Rowling did not have a middle name, so she adopted “K” from Kathleen.

The initials became part of her public identity, although she is generally known as Joanne Rowling in personal and biographical contexts. She also used the pseudonym Robert Galbraith for her Cormoran Strike crime novels. “K” is sometimes incorrectly expanded as Katherine because that is a common name, but Kathleen is the documented family connection.