J.K. Rowling’s birth surname was Rowling.
She was born Joanne Rowling on 31 July 1965, so “Rowling” was her family name from birth. Her parents were Peter Rowling and Anne Rowling. The name is sometimes misunderstood because Rowling’s publishing identity contains an initial that readers may assume represents her own middle name.
Rowling did not originally have a middle name. Her publisher asked her to use two initials because the market was thought likely to respond better to an author name that did not clearly identify a woman. She selected “K” in honor of her paternal grandmother, Kathleen.
After marrying Neil Murray in 2001, she used Joanne Rowling Murray in some contexts, while continuing to publish as J. K. Rowling. The surname “Galbraith” belongs to her later crime-fiction pen name and is not her birth name.