The Daily Show host poked fun at the news network's live two-hour coverage of the flotilla event on Sunday (June 3).
CNN's broadcast featured Piers Morgan and others reacting excitedly over the rain-drenched royal event, much to the bemusement of Stewart.
Comments from Morgan and his colleagues included "This is Britain at its best", "An orgy of excitement", "I'm practically speechless" and "Is this really happening?"
Stewart joked: "Is this somehow the British equivalent of a monster truck show?"
The Daily Show's British 'correspondent' John Oliver excitedly appeared, saying: "Obviously it's impossible to look at what's happening here and not think about what it represents. The sad last gasp of a once-powerful empire, its best days long behind it, desperately trying to conjure up a happier time when it was something more than a decaying relic."
Stewart replied: "A pretty harsh thing to say about your own homeland," to which Oliver responded: "I was talking about CNN."
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Piers Morgan later retweeted the clip, saying: "OK, this is very naughty but very funny..."
However, he also continued to promote his own live coverage, tweeting: "To all those dismayed by the BBC's jubilee coverage, I'll be live on CNN from 1.30pm-4pm - providing all the gravitas you crave."
Photo gallery - Diamond Jubilee concert at Buckingham Palace: