The news comes two weeks after Droga5 Europe’s chief executive, Kevin Dundas, left the London agency amid comments from the founder, David Droga, that the agency needed "to operate in a different way".
Simons is charged with helping Droga5 Europe attract more clients, as well as managing existing accounts, and will help search for a new chief executive to replace Dundas.
In a statement, Droga said: "Nick Simons has proven to be an energetic force, both winning and leading business out of our New York office. We're looking forward to him bringing this Droga5 spirit to London as we strengthen our Global offerings."
Simons began his career in the UK, working at Grey London, M&C Saatchi and Chick Smith Trott.