Charlie Wilson is to depart from his role as chief executive creative director at Ogilvy UK.
The creative, who has been with the business since 1998, has not announced his next step, but staff have been told he is leaving to "explore new opportunities".
Wilson's departure comes just seven months since he was appointed as chief executive creative director, following Ogilvy UK's mass-restructure that saw it consolidate its sub-brands, including the creative shop Ogilvy & Mather, into a single P&L.
During the restructure, Mick Mahoney resigned from his role as chief creative officer. He was followed by Emma de la Fosse who quit her role as chief creative officer to join Digitas.
Despite the upheaval, Wilson remained with the agency, taking on a fresh role after having served as chief creative officer of its direct arm OgilvyOne since 2014.
Ogilvy UK's chief exec Michael Frohlich who was responsible for the restructure has wished Wilson well in the future and thanked him for his time at Ogilvy.
In a statement, he stressed that Ogilvy would continue to evolve its "offering to remain the best solution for its clients' challenges, now and in the future."
Frohlich added: "creativity remains the beating heart of what we do, and we will continue to develop and innovate our creative craft under the stewardship of [chief creative officer] Dede Laurentino and the team."
Earlier this year Laurentino tapped former Facebook creative Shishir Patel as executive creative director, he reports into recently-enlisted chief executive creative director Jules Chalkley.
Ogilvy UK has also changed the way it works on creative briefs in recent months, moving from a less siloed way of working creatively towards a system that cherry-picks talent from across its creative teams to work on different clients.