Speaking at the Intelligence and National Security Summit, Clapper acknowledged that the 2016 election cycle was "sportier than we are used to," but said the 24-hour media cycle and social media were "catastrophyizing" the campaign.
"I know a lot of people who have been feeling uncertainty about what will happen with this presidential transition, been a lot of catastrophizing, if I can use that term, in the 24-hour news cycle and of course of social media. So, I'm here with a message: It will be OK," Clapper told an audience at the Intelligence and National Security Summit in Washington, D.C.
He said any presidential transition is always "a volatile time for our country," and went on to describe the intelligence briefings that are being provided to Hillary Clinton and Donald Trump.
Clapper noted the briefs were provided by career intelligence professionals and not political appointees and that the topics discussed and the candidates' questions would remain confidential. That's because both the opposing campaigns and America's global adversaries would be interested in knowing what the candidate are thinking, Clapper said.
He also lauded the transition process and Harry Truman's decision to brief the candidates after feeling unprepared upon assuming the presidency in 1945.
"I'm really glad as a citizen he made the generous decision to prepare his successor," he said.
Clapper also said he was looking at the classification system and said "we're guilty" of sometimes overclassifying information. He indicated that the "confidential" classification could be eliminated.
Clapper said he had sought recommendations from the intelligence agencies on the issue. "I got an excellent response from CIA yesterday on what we can do to be more transparent, to not to overclassify. There's proposals going around, one of which is why don't we just not bother with 'confidential,' that would somewhat simplify the system."
Clapper discussed recent cyber attacks on the Democratic National Committee but said it was not the first time that kind of hack has been undertaken. "Cyber will continue to be a large problem," he said.
On threats the next administration will likely face, Clapper cited both climate change and terrorism.
Clapper added that ISIS will eventually be suppressed but said that other extremist groups are likely to arise in its place.
The US will be fighting terrorism for the long term, calling it a "perpetual state of suppression for some time to come."
Clapper, who has over 50 years of experience in the intelligence community, struck a valedictory tone in his remarks, poking fun at his age (75) and joking about attending the inauguration of John Adams and briefing the first candidates to receive intel briefs during the campaign in 1952.
Asked if anything still surprised him, he responded "not really" and said he plans to "sleep" when asked about his post-government plans.