IFC announced that it has picked up a second and third run of the Helen Mirren-presented fake documentary programme, based on positive "buzz" for season one, reported Digital Spy.
The network is also extending season one's six-episode run to seven installments, in order to fit in a surprise finale.
IFC president Jennifer Caserta said, "This two-season renewal ahead of the show's initial debut is a huge nod to the creative and comedic genius of Fred, Bill and Seth.
Each episode of "Documentary Now!" tells an entirely fictional story in the style of a mockumentary.
Season one includes parodies of classic documentaries like "Nanook of the North", "Grey Gardens" and "The Thin Blue Line".