What middle name does J.K. Rowling share in her full name?

J.K. Rowling’s middle name is Kathleen.

She was born Joanne Rowling, and her name is commonly written as Joanne Kathleen Rowling. The initial K was added before publication of Harry Potter and the Philosopher’s Stone because her publisher wanted two initials for the author name. Rowling did not originally have a middle name.

The K stands for Kathleen, the name of her paternal grandmother. Rowling has explained that “J.K. Rowling” was a publishing name rather than a completely different personal identity. She is also known as Jo among friends and readers.

The name is sometimes mistaken for “Joanne Kathleen Rowling” having been her birth certificate name from birth. The distinction matters because the added middle initial became part of the author branding used on the Harry Potter books. Her pen name Robert Galbraith is separate and was used for crime fiction.