Bennett-Day will be tasked with developing the creative offering of Havas EHS, including its strategic approach combining creative, data and digital that the agency calls FULCRM.
At DraftFCB, Bennett-Day worked on accounts including Coca-Cola Europe, Beiersdorf and eBay. He previously worked at Skive on clients such as Carlsberg and Innocent.
Matt Fanshawe, the global brand director and group chief operating officer at Havas EHS UK, said: "Having Steven on board will play a key role in helping to transform the agency’s creativity."
Clifton, the former head of creative, has left the agency.
Havas EHS made a number of senior appointments at the end of last year, including Peter Sells, the former head of mobile at Bartle Bogle Hegarty, for the same role.