Van Gestel will join JWT in the New Year as its ninth managing partner.
He spent three years at Leo Burnett running the Heinz account, and worked on winning pitches for the pan-European Nintendo account. He also helped launch the GameCube and GameBoy Advance consoles and games in the UK and Europe.
Most recently, van Gestel helped set up Magellan, a Bcom3 subsidiary, which was created to develop regional campaigns for Toyota and to launch the Corolla. His telecoms experience includes launching a mobile brand for the Finnish Telecom company Sonera.
JWT's managing director, Ros King, said: "Alex is a proven strategic thinker with a great track record in building and managing brands and in generating mould-breaking creative work."
Van Gestel said: "It is a very exciting challenge to be joining JWT to work on Vodafone at this time. My first role will be to drive the strategic output and raise the bar creatively in line with the agency's already expressed ambitions."