The Book of Bill

The Book of Bill is a teen-audience science fiction book published by Hyperion Avenue Books, based on the children's animated television series Gravity Falls. Written by series creator Alex Hirsch, the book retells its story from the perspective of primary antagonist Bill Cipher (who is credited as a co-writer and artist), extending before and after the events shown in the series.

First announced in December 2023, the book was released on July 23, 2024. An exclusive edition with 16 extra pages of behind the scenes production art and drawings is available from Barnes & Noble. The Book of Bill was generally positively received by fans and the media. The book appeared on The New York Times Best Seller list in July 2024, and remained through January 2025.