John Bolton, a staunch conservative who served in the Trump administration for 17 months, said he considered the president "did incite the riot and he did it with the intention that they find a way to prevent Congress from certifying the vote of the electoral college".
In an interview with ITV News at Ten Presenter Tom Bradby, Mr Bolton said Mr Trump's actions were "an impeachable offence" but added there may not be time to complete the process.
Hundreds of angry demonstrators fought past police and breached the home of America's federal government to demand lawmakers stop November's presidential election from being ratified.
President Trump had called on protesters to remain peaceful, but was accused of encouraging them while the protest was going on.
The 74-year-old has also refused to concede the election and repeated unsubstantiated claims that it was stolen and rigged and was accused of encouraging them while the protest was going on.
Debating what options are now open for US politicians to hold the outgoing president to account, Mr Bolton said "the very worst thing you can do to Donald Trump is to ignore him".
Pressed on whether he thought Mr Trump would run for re-election in 2024, Mr Bolton told ITV News: "I would be willing to bet almost any amount of money that he will not run for election in 2024."
The former national security advisor, who has written a memoir - blasted by President Trump - of his time in White House, said his former boss "will talk about it all the time to keep himself in the limelight".
But added: "Running is almost entirely out of the question - he doesn't want to risk losing again."
Mr Bolton added there needed to be "a very serious conversation" in the American Republican party about how to "fix the damage that he [Donald Trump] has done".
Damage, Mr Bolton said, the president "continues to do with his words and his actions".
"Donald Trump is an aberration on the American political scene," he said.
"He did not cause all of this polarisation, that's for sure, but he's made it much, much worse and I think his disappearance from the political scene will be a big, big plus."
His comments follow those of former US attorney general William Barr, who told ITV News that questioning the legitimacy of the presidential election result "precipitated the riots" in the US Capitol on January 6.