On Cinema (also called On Cinema at the Cinema) is an American comedy web series and podcast starring Tim Heidecker and Gregg Turkington as amateur film critics. The duo appear as fictionalized versions of themselves. The show started as an independently released podcast from 2011 to 2013, before being picked up as a professionally produced web video series by Thing X in 2012, continuing after the site merged with Adult Swim's website in 2013. The show moved to HEI Network, an independent service, in 2021, with funding given by subscriptions and special event ticket purchases.

On Cinema at the Cinema is the hub of a metafictional 'fictional universe', including the original podcast, 15 seasons of the web video series, yearly live Oscar specials, a spin-off limited series entitled "The Trial", the spin-off series Decker, a movie review app, an On Cinema Live! tour, and a film entitled Mister America.

On Cinema also features guest actors, some of whom play fictionalized versions of themselves, most notably actors Joe Estevez and Mark Proksch. The show and fictional universe have a dedicated cult following of fans who play along with the storylines via social media, often taking sides as "Timheads" or "Greggheads", or "Unityheads" for those that do not take a side. Heidecker and Turkington also started Decker-Con, where they appear in character and interact with fans.