Hermione Jean Granger is a fictional character in J. K. Rowling's Harry Potter series. She first appears in the novel Harry Potter and the Philosopher's Stone (1997), on the Hogwarts express as a first year student on her way to Hogwarts. After Harry and Ron save her from a mountain troll in the girls' restroom, she becomes best friends with them and often uses her quick wit, deft recall, and encyclopaedic knowledge to lend aid in dire situations. Rowling has stated that Hermione resembles herself as a young girl, with her insecurity and fear of failure.

Joanne Rowling ; born 31 July 1965), known by her pen name J. K. Rowling, is a British author and philanthropist. She wrote Harry Potter, a seven-volume fantasy series published from 1997 to 2007. The series has sold over 600 million copies, been translated into 84 languages, and spawned a global media franchise including films and video games. The Casual Vacancy (2012) was her first novel for adults. She writes Cormoran Strike, an ongoing crime fiction series, under the alias Robert Galbraith.