J. R. R. Tolkien
John Ronald Reuel Tolkien was an Oxford don and the author of The Lord of the Rings. While working at a garden centre, Fitz Kreiner had a conversation with a woman who incorrectly named him as R. J. Tolkien. Fitz convinced her that the character of Frodo had been named after a woman with whom Tolkien had a relationship. (EDA: The Taint)
Tolkien briefly met the Eleventh Doctor and Amy Pond during a readthrough of The Professor, the Queen and the Bookshop by C. S. Lewis. Although he's never called by his full name, he's refered to as John, and, according to Amy, he didn't find C. S. Lewis's book very interesting because "it didn't include half-a-dozen made-up languages". (DWM: The Professor, the Queen and the Bookshop)