Hughes will be responsible for leading the strategic marketing partnership between Publicis and HP. She will manage the Publicis agencies' executions for the brand in all communications throughout the region.
Hughes spent six years at Visa International, having joined the company in 1998, and was responsible for a £90 million communications budget. She led the brand's strategy and maximised its value in the European Union.
Richard Pinder, the chief operating officer at Publicis, said: "Karen's unique experience in managing change and building and operating a network will be of huge value as she now takes the reins."
Hughes added: "The challenge will draw on all aspects of my experience to date, but still offer great learning."