Season 1

{{Season Fridays 9:00pm EST (Eps 13-21) The first season of Gravity Falls officially premiered on June 29, 2012, but the first episode aired as a sneak peek on June 15, 2012. The first episode was then available for free download on iTunes. The season consisted of 20 episodes.
 * bg = #F76224
 * image = Opening photos.png|
 * caption = Various creatures from season 1 in the opening.
 * country = United States
 * episodes = 20
 * channel = Disney Channel
 * run = June 15, 2012 - August 2, 2013
 * time slot = Fridays 9:30pm EST (Eps 1-12)
 * next=

Twin brother and sister Dipper and Mabel Pines are in for an unexpected adventure when they spend the summer with their great-uncle in the mysterious town of Gravity Falls, Oregon. Upon their arrival, Dipper and Mabel's huckster great-uncle, also known as Grunkle Stan, enlists the siblings' to work at the The Mystery Shack, a "fun" tourist trap he owns that overcharges unsuspecting customers, with no pay. Although Dipper and Mabel quickly discover The Mystery Shack itself is a hoax, they sense there is something strange about their new town and together they begin to unlock the secrets of Gravity Falls.

Main cast

 * Jason Ritter as Dipper Pines
 * Kristen Schaal as Mabel Pines
 * Alex Hirsch as Grunkle Stan and Soos
 * Linda Cardellini as Wendy Corduroy

Recurring cast

 * Dee Bradley Baker as Waddles
 * Thurop Van Orman as Gideon Gleeful
 * TJ Miller as Robbie
 * Kevin Michael Richardson as Sheriff Blubs
 * Keith Ferguson as Deputy Durland
 * John DiMaggio as Manly Dan
 * Alex Hirsch as Old Man McGucket
 * Jennifer Coolidge - Lazy Susan
 * Will Forte as Cute Biker
 * Stephen Root as Bud Gleeful
 * Gregg Turkington as Toby Determined
 * Niki Yang as Candy Chiu
 * Carl Faruolo as Grenda
 * Jackie Buscarino as Pacifica Northwest

Guest Stars

 * Coolio as Wax Coolio
 * Larry King as Wax Larry
 * John Oliver as Sherlock Holmes
 * Alfred Molina as Multi-Bear
 * Jessica DiCicco as Tambry
 * Michael Rianda as Lee/Thompson
 * Scott Menville as Nate
 * Justin Roiland as Blendin Blandin
 * Matt Chapman as Mermando
 * Brian Bloom as Rumble McSkirmish
 * Lance Bass as Sev'ral Timez

Episodes

 * See also: The Episode Guide

Production
The series, created, directed and executive-produced by 2007 California Institute of the Arts (CalArts) graduate Alex Hirsch (Fish Hooks, The Marvelous Misadventures of Flapjack), is a production of Disney Television Animation. Set in the Pacific Northwest woods of Oregon, the animated series features supernatural elements of adventure and mystery, inspired by the real-life summer trips shared by Hirsch and his twin sister while visiting relatives as kids.

Alex Hirsch has provided conflicting information regarding the number of episodes in the first season. On August 8, 2012, he said there would be 21 episodes. However, on July 7, 2013, he implied there are only 20 episodes as Dreamscaperers is the 19th episode. On July 8, 2013, he confirmed his original statement of 21 episodes was incorrect.