Ellis will join Droga5’s Soho office as head of strategy in October.
The agency is yet to win any local clients but a spokeswoman declined to comment on whether Ellis would be working on global clients such as Coca-Cola and Mondelez International.
At TBWA Ellis led the global brand strategy for the hotel chain Four Seasons, and has led accounts for Sony’s PlayStation, Nissan Europe and Absolut. Before joining TBWA’s London office, Ellis was head of media arts at the agency’s base in Manchester.
Ellis said: "I've always admired Droga5 from afar in terms of its ability to solve the business problem at all costs, using all of culture as their canvas. I hope to both live up to and progress an already remarkable story. The desire is clearly there to raise the bar once again."
Droga5 launched in London earlier this year after hiring 180 Amsterdam’s managing partner and president Kevin Dundas as its chief executive.
Dundas added: "Toto possesses that rare skill that goes way beyond strategic insight to strategic liberation. He is a key addition to our management line up and we are fortunate he is joining the party."