Fox News
"John's 30 years of experience and reputable journalism skills were showcased throughout his coverage from the campaign trail during the 2016 election season," said executive vice president Jay Wallace in announcing the news.
Wallace added: "We are proud to welcome him to the Washington bureau and look forward to him leading the network's coverage of incoming President-elect Donald Trump."
Roberts said Trump's presidency "will be the predominant news story worldwide" in the coming years and added that he was "honored" the cable news network had allowed him a "front-row seat to history as it all unfolds."
Ed Henry had previously served as chief White House correspondent for Fox News before he was suspended in May after a tabloid report revealed he had been carrying on an extramarital affair with a Las Vegas hostess. After a four-month break, Henry returned to the network as chief national correspondent, leaving his previous role at the White House unoccupied.
Roberts joined Fox News in 2011 as senior national correspondent after serving as a co-anchor on CNN's "American Morning." Henry, who has covered every presidential race since 1996, focused on the Republican primaries in 2016 before shifting to Trump's campaign during the general election.
The new role comes amid other changes at Fox News in the post-Roger Ailes era. The network recently signed Democratic fundraiser Robert Wolf as a contributor, and Tucker Carlson took over the 7 p.m. time slot with his new show.