Vadot also served as area export manager for the BIC Group in Central/Eastern Europe, North Africa and the Middle East.
Kurt Thompson, Synovate chief executive for Central/Eastern Europe and the Middle East, said: "Synovate has long been the industry leader in Saudi Arabia. Jerome's extensive management experience and commercial leadership skills will be a great asset as we further strengthen our position in this key market."
Separately, Synovate has promoted Simon Duval-Kieffer to managing director of its Czech Republic division.
Duval-Kieffer will move to Prague from Synovate South Korea, where he has spent six years. His first role at the company was project director and later he became associate director. The time was split by a two-year posting at Synovate Malaysia.
Thompson said Duval-Kieffer's appointment comes as the company invests in more staff and new facilities in Prague.
He said: "The Czech market holds tremendous potential, and with Simon's experience in fast-growing Asian markets, we're confident he will make the most of those opportunities."