Kenneth Dibble, the Charity Commission's long-serving legal director, is to step down from his executive position to take up a role on its board from March.
Dibble has been chief legal adviser and legal director at the commission for the past 15 years.
The Department for Digital, Culture, Media and Sport said Dibble would assume the role of legal board member on the commission board for an initial three-year period.
He will succeed the barrister Orlando Fraser, whose term on the Charity Commission board is due to come to an end this month.
Fraser faced scrutiny after Third Sector revealed comments he made in an internal commission email, in which he urged the regulator to conduct a "look-see" investigation of the Joseph Rowntree Charitable Trust after it gave funding to the advocacy group Cage.
Dibble, who will be paid £350 a day for his work on the commission board, is a qualified barrister and a visiting lecturer on charity and regulatory law and practice at Cass Business School.
The DCMS said that under Cabinet Office rules any significant political activity carried out by an appointee in the previous five years must be declared. Dibble had declared no such activity.
The commission is expected to begin the process of appointing his successor as legal director in the new year.
William Shawcross, whose term as chair of the Charity Commission will end on 31 January, said: "Kenneth has unparalleled mastery of charity law, a thorough understanding of modern regulation and extensive experience of senior executive leadership.
"The commission, and the public, will benefit tremendously from his continued service. As my term of office as chairman comes to an end, this appointment adds to my confidence that the organisation will be excellently guided in the future."
In a statement, Dibble said he was honoured to be appointed to the commission’s board.
"Charities, and by extension the commission as their regulator, play a central role in our society," he said. "Maintaining the legal integrity of the commission’s regulatory work is critical, and I look forward to continuing to support that element, and shaping the commission’s future, in my new role as legal board member."