Sandberg has served as chief financial officer of Millward Brown North America for the past 11 years.
He is based in the company's Naperville, Illinois office.
Eileen Campbell, chief executive officer of Millward Brown Group, said: "For over a decade, Dave has played a crucial role in the growth of our North American business.
"Dave's financial and strategic vision has always been global in scope so his move to the Group CFO position is a perfect fit."