US President-elect Donald Trump was quick to refute the conclusion, saying hacking did not impact the November 8 presidential polls outcome.
"We assess Russian President Vladimir Putin ordered an influence campaign in 2016 aimed at the US presidential election," the Director of National Intelligence said in a report.
The 31-page report alleges that Russia's goals were to undermine public faith in the US democratic process, denigrate Democratic presidential candidate Hillary Clinton and harm her electability and potential presidency.
Obama had ordered a comprehensive probe into allegations of Russian hacking the Democratic party's email system.
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A team of intelligence officials briefed Trump and Vice President-elect Mike Pence on the report in New York.
"While Russia, China, other countries, outside groups and people are consistently trying to break through the cyber infrastructure of our governmental institutions, businesses and organisations including the Democrat National Committee, there was absolutely no effect on the outcome of the election including the fact that there was no tampering whatsoever with voting machines," Trump said in a statement after the meeting.
"I will appoint a team to give me a plan within 90 days of taking office. The methods, tools and tactics we use to keep America safe should not be a public discussion that will benefit those who seek to do us harm. Two weeks from today I will take the oath of office and America's safety and security will be my number one priority," Trump said, adding that there is a need to aggressively combat and stop cyberattacks.