He replaces Lord Davies, who stepped down as chairman following the acquisition of Chime last year by US private equity firm Providence and WPP for £374 million.
Walsh has taken on various board roles since leaving Diageo in 2012. He is also the chairman of Compass Group, the global catering company and Avanti Communications Group. He also joined the board of HSBC, the global banking giant, in November 2015.
Chime’s sports division, CSM, is chaired by Lord Coe, the chairman of the IAAF, the world athletics governing body.
Christopher Satterthwaite, the chief executive of Chime Communications, said: "We are delighted that Paul will be joining Chime.
"He has unrivalled experience in growing businesses on an international scale and we will benefit greatly from this and his understanding of how sport, entertainment and communications can transform brands."