Joanna Shields, one of Facebook's most senior executives, will be leaving the firm in January to spearhead the growth of London's Tech City, the UK government's initiative to create a tech start-up cluster that will lead European innovation to rival Silicon Valley.
Shields, currently Facebook's managing director of Europe, will soon become the chief executive of the Tech City Investment Organisation (TCIO).
The TCIO was set up in April last year by the government's Trade and Investment department to support the growth of start-ups in East London. The TCIO assists with securing foreign investment in Tech City and raising its profile internationally.
Prime minister David Cameron has said he was delighted by the appointment.
"The success of Tech City shows just what can happen when we back some of our most innovative and aspiring companies to grow, helping the UK compete and thrive in the global race," he said.
"Shields's experience will be hugely valuable in supporting Tech City as it goes from strength to strength, and as a business ambassador promoting the UK around the world."
Before joining Facebook, Shields was president at AOL, and previously served as chief executive of Bebo. She has also been Google's European managing director.
"Throughout my career I have had the privilege of working with great entrepreneurs and innovators to create thriving new businesses and industries," said Shields.
"The seeds have been sown in East London for a dynamic and successful cluster: we have the infrastructure, the technology and the talent, now we need to accelerate the growth. With the right boost now, there is no reason why we can't make London the number one location for tech in the world."
Shields will not be discussing the new appointment publicly until she takes on the new position next year, the TCIO told V3.
She will be taking over from Eric van der Kleji, who stepped down over the summer after two years in the job, and is now working for the Canary Wharf Group.
Ben Southworth was appointed the deputy chief executive officer of the TCIO in July.
Shields will also take up positions as Business Ambassador for the Digital Industries and chairman of the Tech City Advisory Group.