Antonia Romeo has been named as the new permanent secretary of Liam Fox's Department for International Trade.
Romeo, who has spent the past six months as the UK's consul general in New York, will take up post on March 27, the DIT said, but will continue to work in the United States until the summer.
The incoming DIT chief, who will succeed interim perm sec Sir Martin Donnelly at the department tasked with promoting exports and forging post-Brexit trade deals for the UK, has long been viewed as one of Whitehall's rising stars.
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Her appointment follows a decision by international trade secretary Liam Fox to open the recruitment process up to overseas candidates.
But, in the event, Fox's department has opted for an official with extensive civil service experience, while setting out plans to create a second perm sec post to provide "expert" trade negotiation advice.
Romeo joined the civil service as an economist in 2000, and went on to serve as principal private secretary to Labour's Lord Falconer at the Ministry of Justice.
She has also served as a director at the Foreign Office; as director general for criminal justice at the MoJ; and, most recently, as head of the powerful Economic and Domestic Affairs Secretariat at the Cabinet Office, a role seen as a stepping-stone to perm sec level.
Announcing Romeo's appointment, Fox said the new perm sec would play "a vital role in leading the department to deliver the UK’s trade agenda at home and abroad".
He added: "We are harnessing the very best of homegrown and international talent and I’m delighted to welcome Antonia who brings with her extensive leadership and policy expertise that will help the UK to take advantage of the many global trading opportunities before us."
Cabinet secretary Sir Jeremy Heywood, said Romeo had "done an excellent job in a number of roles across government" and said she would bring "a strong blend of leadership and Whitehall skills at an exciting time for the department".
The DIT said it would also beef up its leadership team with the creation of a new "expert second permanent secretary post", reporting directly to Romeo.
"The global search for an international trade negotiating expert to fill this post will open soon," the department said in a statement.
After decades of trade policy being determined at European Union-level, Whitehall has a widely-acknowledged shortage of trade negotiation expertise as Britain prepares for its exit from the EU.
In a statement on her new role, Romeo said it was "a privilege to have been appointed to lead the department as we work to promote the UK as an outward-facing, free-trading global nation".
She added: "International trade and investment are central to UK prosperity and growth as we exit the European Union.
"I look forward to working with the secretary of state, ministers and staff of the department as well as colleagues across Whitehall, on this challenging agenda."
According to a job specification posted with headhunting firm Russell Reynolds, Romeo can expect to command a salary of around £160,000.