Mark Barber, Radiocentre's planning director and the force behind studies such as Re-evaluating Media and ROI Multiplier, is stepping back after more than 25 years.
Simon Pakenham-Walsh, formerly of River Island and Sweaty Betty, becomes the Premier League's first chief technology and data officer as it moves to the cloud and builds AI fan products.
Jon Cook is leaving as global CEO of VML and WPP Creative after three decades, staying until March 2027 to hand over to North America chief Eric Campbell.
Anna MacDonald, who ran Guinness in Great Britain for five years, becomes marketing and category director for Diageo GB as Ursula Mejía Melgar leaves for Coca-Cola.