Gaiman said he was "amazed and thrilled" by the honor.
"I've never written a book before that was so close to my own heart -- a story about memory and magic and the fear and danger of being a child," said Gaiman. "I wasn't sure that anyone else would like it.
I'm amazed and thrilled that so many other people have read it, loved it, and made their friends read it too. Winning a National Book Award was thrilling; discovering that the public have made 'The Ocean at the End of the Lane' their Book of the Year is somewhere out beyond wonderful. Thank you to everyone who voted."
E.L. James' erotic bestseller "Fifty Shades of Grey" won last year's prize, the BBC said.