Coen, 34 joins from Diageo's global brand strategy team nicknamed 'Dweebb' (the Diageo Way of Brand Building), which devises ways of building brands effectively on a global scale.
Reporting to Guinness UDV marketing director Syl Saller, he will take control of all UK marketing for Guinness Draught, Extra Cold and bottled Guinness.
He will also take responsibility for the international 'Believe' campaign, created by the BBDO network.
Coen has spent the past three years at Dweebb. Before that he was responsible for the quality of Guinness in pubs as marketing controller for ales and lagers. He also spent two years at Pedigree Petfoods.
Coen replaces David Smith who is moving sideways into a commercial role as business unit director for multiple retail groups, as part of a marketing reshuffle within Guinness UDV (Marketing, April 23).
Guinness split its £250m global ad account between BBDO and Saatchi & Saatchi last year.