He replaces Helen McRae, who is going on maternity leave but plans to return to the agency at the end of the year in a new management role.
Pullan will lead a 500-strong team across communications planning, digital, branded content, analytics, ROI and media buying. He will work alongside Mindshare's three regional heads in North America, Europe and Asia.
Pullan, who joins from Surrey County Cricket Club where he held a senior commercial role, is a former chief marketing officer at Manchester City Football Club, president of client services at Isobar and strategic marketing and brand development director at Emap.
Separately, Mindshare has hired Jorge Guglielmone as its chief executive and leader of Mindshare Latin America. He joins from ZenithOptimedia and replaces David Byles.