He said it did not leave Blair with a "leg to stand on", was "brutal" on the security services, and "pregnant with significance for the British state because something clearly went significantly wrong."
"He has fundamentally gone to the heart of the matter, he's shown that Mr Blair's government took Britain into an unnecessary war," said Oborne, speaking after journalists had seen the report for the first time.
"It was a war, and Sir John Chilcot makes no bones about this, that led to the most terrible and devastating consequences.
"Some people might be disappointed that he doesn't say that Tony Blair lied. It seems to accept his protestations that he believed what he was saying but on the other hand it shows again and again that what Mr Blair said was not actually true."
Watch Oborne's full reaction above.