Gravity Falls
In 2012, Hirsch created the series Gravity Falls for Disney Channel. The series, set in the fictional town of Gravity Falls, Oregon, premiered in June 2012 with a voice cast including Jason Ritter, Kristen Schaal, and Hirsch himself. Over the course of the series, he provided the voices of Grunkle Stan, Soos Ramirez, Old Man McGucket, Bill Cipher, and various minor characters. The series was moved to Disney XD in 2014. It would go on to win a BAFTA Children's Award and an Annie Award in 2015 and was nominated for several other awards (including a Peabody Award in 2016). Hirsch ended Gravity Falls in February 2016 to pursue other projects.
In July 2016, Hirsch hosted a global treasure hunt (known as the "Cipher Hunt") for Gravity Falls fans with clues hidden throughout the world including in the United States, Japan, and Russia. The goal of the hunt was to find a statue of the Gravity Falls character, Bill Cipher. After two weeks, fans of the series discovered the statue in Reedsport, Oregon. The hunt coincided with the release of Hirsch's tie-in book, Gravity Falls: Journal 3, which was released on July 26, 2016, and eventually became a No. 1 New York Times Best Seller and appeared on The New York Times Best Seller list for nearly a year. A special edition of the book was released on June 13, 2017, and limited to 10,000 copies. The Gravity Falls: Journal 3 Special Edition contains blacklight writing, parchment pages, a monocle, removable photos and notes, and other features that were not included in the regular edition of the book. Marketing for The Book of Bill revealed that Gravity Falls: Journal 3 has sold more than 1.3 million copies as of January 2024.
In February 2018, Hirsch used his Twitter account to announce an official Gravity Falls graphic novel, through a series of puzzle pieces that he would release throughout the day. When put together, the puzzle pieces revealed the cover of Gravity Falls: Lost Legends; 4 All-New Adventures! which was written by Hirsch was released on July 24, 2018, and also became a New York Times Best Seller.