The agency has also recruited Karen Selby as practice lead for the distribution sector.
Robinson returns to Grass Roots after eight months at marketing services firm Intuitive Group, where he was group account director. He worked at Grass Roots for seven years, between 2005 and 2011; before which he was at Archer Young Marketing.
Selby has a background in venue-finding and event management at marketing agencies.
Warren Hillier, Grass Roots Eventcom's co-director, said: "Both Kevin and Karen have impressive track records in client solution development. They very much share our vision for the future and we're delighted to have them on board."