Based in London, he will report to Group M's head of trading, Jurgen Blomenkamp.
Zonfrillo will take up his new post in August after ten years at Mindshare. He has been responsible for leading trading for Mindshare clients including News International, Nike and Motorola.
Zonfrillo also oversees the trading for the Group M and CHI & Partners joint venture MCHI. Its clients include the Carphone Warehouse and Britvic.
Jed Glanvill, the chief executive of Mindshare, said: "Andy has made an immense contribution to Mindshare over the last decade."
Zonfrillo added: "I look forward to continuing to work with Mindshare in my new role and wish the agency even more success in the future."