According to the UK Daily Telegraph. Joanne Rowling, better known by her initials J K, does not have a middle name, according to her birth certificate. The use of the author's initials instead of her full name was a marketing ploy designed to make her work acceptable to boys, who actively choose not to read books by women. Yesterday, her birth certificate, published by a Bristol newspaper, shows her parents registered her as Joanne Rowling. Her publicity agents have said her full name is Joanne Kathleen Rowling. funtrivia.com Rowling's full name is Joanne Rowling, not, as is often assumed, "Joanne Kathleen Rowling." Before publishing her first volume, Bloomsbury feared that the target group of young boys might be reluctant to buy books written by a female author. They requested that Rowling use two initials, rather than reveal her first name. As she had no middle name, she chose K from her grandmother's name Kathleen, as the second initial of her pseudonym. The name Kathleen has never been part of her legal name[45]. She calls herself "Jo" and claims, "No one ever called me 'Joanne' when I was young, unless they were angry"[46]. Her surname is pronounced like "rolling" wikipedia When the first Harry Potter novel was published, the publisher asked her to use initials rather than her first name because boys would be biased against a book written a woman. Since she only had one given name, they then asked her to make up another initial; she took K. from her favorite grandmother, Kathleen. imdb information Her name Rowling's full name is Joanne Rowling, not, as is often assumed, "Joanne Kathleen Rowling." Before publishing her first volume, Bloomsbury feared that the target group of young boys might be reluctant to buy books written by a female author. They requested that Rowling use two initials, rather than reveal her first name. As she had no middle name, she chose K from her grandmother's name Kathleen, as the second initial of her pseudonym. THE NAME KATHLEEN HAS NEVER BEEN PART OF HER LEGAL NAME. entry from answers.com quick thinker: do some more research. She took the K from her grandmothers name but kathleen was never part of her name.

Joanne Kathleen Rowling---- Most oftenly refered to as J.K. Rowling. At birth Joanne Rowling had no middle name. Once she became aware of this she took the name of her grandmother (Kathleen). So, that is where you get the initials of J.K. Rowling

Her full name is Joanne Kathleen Rowling

I've never known the answer to that question and oddly enough it never occurs to me to look it up. Lol:)