Speaking on his Comedy Central programme The Daily Show, Stewart said of O’Reilly that: "Misrepresenting the zone he’s in is kind of his hook. ‘You’re in the No-spin zone’ are the words he utters right before throwing out to some jackass who disproves global warming by wandering around Boston pointing at snow, on a network whose slogan (‘Fair & Balanced’) is a textbook case of trolling."
Comedian and political satirist Stewart continued: "Why don’t we just agree that a good amount of the personal anecdotes from our media figures are seasoned with bullshit, and let's just move on?"
He went on to say that watching the network's "two-dimensional battle for America's soul" had "aged him" and that watching it is "killing me."
Stewart has previously clashed with O'Reilly, who presents the show The O'Reilly Factor on Fox News. The two locked horns in a debate in the build up to the 2012 Presidential elections.
O'Reilly allegedly told a New York Times reporter earlier this week that he would "come at him with everything he had" after being questioned over allegations that he may have embellished the proximity of his vantage point while covering the Falklands war.
Stewart's fresh accusations branched into an assault on America’s conservative movement.
He said that while conservatives “purport to want to fix things” they were not looking to strengthen the education system, make science more verifiable, allow voting to become more representative or the government more efficient or effective.
“They just want all of these things to reinforce their partisan ideological conservative viewpoint. Because, in their mind, the opposite of ‘bad’ isn’t good. The opposite of ‘bad’ is ‘conservative’”
Stewart posted a Vine on The Daily Show’s Twitter page that claims to show 50 lies told by Fox News in six seconds.
50 Fox News lies in 6 seconds. (Tap the screen to pause) https://t.co/n0BBeoYCzTThe Daily Show (@TheDailyShow) February 26, 2015
Stewart recently announced that he will be stepping down as the host of The Daily Show later this year, which he has presented since 1999.
People reported to be lined up as the new host for the show include comedians Louis CK, Chris Rock, Amy Poehler and Sarah Silverman, while British comedian John Oliver has ruled himself out.
Fox News are yet to respond to request for comment.