Hicks reportedly urged Administration officials, including the President, to be more transparent in characterising a June 2016 meeting among Trump, presidential son-in-law Jared Kushner, campaign chairman Paul Manafort and Russian representatives who allegedly were offering negative information about Hillary Clinton.
Trump reportedly dictated a misleading public statement released by Hicks characterising the encounter as a "short, introductory meeting" in which the participants "primarily discussed a programme about the adoption of Russian children."
Hicks was formerly director of communications for the Trump Organisation. She was an early recruit to Trump's campaign, joining it several months before he announced his candidacy in June 2015.
At New Fox, Hicks will succeed two executives who oversaw 21st Century Fox's communications when Fox News was beset by multiple sexual harassment allegations, including against its co-founder Roger Ailes and top star Bill O'Reilly. The executives, Julie Henderson and Nathaniel Brown, are not joining New Fox.
Hicks will be based in Los Angeles, according to an announcement by Viet Dinh, the company's chief legal and policy officer.
The appointment was cheered by White House press secretary Sarah Huckabee Sanders, who tweeted: "Fox won't find anyone smarter or more talented than Hope Hicks. So happy for my friend. They are beyond lucky to have you and the East Coast misses you already."
New Fox also appointed Danny O'Brien as its head of government relations. O'Brien has previously been chief of staff to three Democratic senators: Joe Biden, Robert Menendez, and Robert Torricelli. He was also staff director for the Senate Foreign Relations Committee and was most recently an executive at General Electric.