The actor, 63, said his foul-mouthed spin doctor Malcolm Tucker from the political satire would be “too good” to exist in the current political world.
Mr Cummings, the Prime Minister’s chief aide until he walked out of Downing Street in November, has made a series of claims about the Government’s inner workings and its response to the coronavirus pandemic.
Speaking to the BBC’s The Andrew Marr Show, Capaldi was asked how Tucker would have responded to Mr Cummings’ claims.
He said: “I can’t really say what Malcolm would say because the language would be unuseable.
“But I think in many ways what we are seeing… is like the The Thick of It because of the levels of vitriol and absurdity and ego that are going on.
“At the same time it is beyond that. It is a kind of tragicomic situation without the comic bit and I think it is beyond a joke.
“These are the people who are supposed to look after us and they are behaving in a way that is not funny.
“So I don’t even think Malcolm would exist in this world. He is too good for this world.”
The cult political satire started life on BBC Four in 2005 and ended on BBC Two in 2012.
Series creator Armando Iannucci ruled out a revival of the satire in 2016, saying the “alien and awful” world of politics at the time would be hard to match.