The Department for International Trade has appointed BT's Dan Ramsay as director of the "GREAT" campaign that promotes the UK overseas.
The "GREAT" campaign, which runs across 144 countries, has a brand value of £271m, the DIT said, and is the government's "most ambitious international marketing campaign ever".
Ramsay replaces interim director Claire Pimm. At BT, Ramsay was multi-brand marketing director.
Commenting on his appointment, he said: "I am honoured to be leading such a prestigious and high-profile campaign that makes such a massive difference to our nation.
"The opportunity to promote and grow a very special brand – the UK itself – means this is a truly unique marketing role."
Antonia Romeo, permanent secretary at the DIT, added: "Dan Ramsay brings significant marketing and campaigns experience from the private sector into the civil service, having led high-profile campaigns such as the launch of BT Sport.
"I am delighted that he will be leading the 'GREAT' campaign at such an important juncture for the UK."
Ramsay worked at BT for 12 years but only took on his most recent role at the company in November 2018, when a marketing management reshuffle saw his role change from consumer marketing director for BT.
As part of the restructure, EE director of brand marketing Pete Jeavons became director of marketing communications for BT’s consumer division, responsible for leading all marketing communications across both BT and EE.
Those changes followed the promotion of Pete Oliver, previously sales and marketing lead for the BT brand, to the top job of managing director of marketing, with responsibility for both BT and EE. Jeavons later became interim group brand director in May when Zaid Al-Qassab left to join Channel 4.
Campaign has contacted BT for comment.