Cochrane will report to Josh Berger, president and MD at the firm and will be responsible for marketing across a range of divisions including Warner Bros Consumer Products.
The appointment has been made as part of a strategy to maximise profitability and ensure a consistency of strategy and communications.
Cochrane will join the executive board and be accountable to the UK MDs and senior divisional management when her activities relate to their specific business units. She will manage a team of 44 staff.
Berger commented: “Polly is one of the most respected marketers of her generation with a proven track record of innovation and creativity that’s second to none. I’ve no doubt she will inspire our talented UK marketing group to ever greater heights, and be a superb addition to WBUK’s senior management team.”