Cambridge University’s James Orr was described as “a brilliant academic, theologian, thinker” by Reform’s head of policy Zia Yusuf.
Mr Yusuf announced the associate professor of the history of religion at Cambridge had joined Reform in a post on social media site X.
The senior Reform figure added: “He has been a bastion of common sense and patriotism at Cambridge University.
“He has become a close friend, and is someone who I believe will have a pivotal role in shaping the future of this country.”
He continued: “James is now a senior member of our team, a senior adviser to Nigel Farage and he will bring even more talented patriots to the Reform family.”
Though not a well-known public figure, Mr Orr has been influential upon the philosophy of the Trump administration.
Vice president JD Vance once described him as his “British sherpa”.
The two are reportedly close friends, with Mr Vance having visited and stayed with the British academic at his home in Cambridge.