Lancaster joins after three years as planning director at Leo Burnett, where she was in charge of strategic development across the regions for Procter & Gamble and contributed to the agency's new business development.
Prior to this, she was a planning partner at Rainey Kelly Campbell Roalfe/Y&R London, where she managed the planning department and worked on accounts for Lloyds TSB, Virgin Atlantic, Eurostar and Thetrainline.com. She has also held senior positions at M&C Saatchi and Ogilvy & Mather.
Blue Marlin, which handled the rebranding of Vaseline's Intensive Care Rescue range earlier this month, said Lancaster's joining would give the agency leadership in key areas of its business.
Phil Langford, UK managing director at Blue Marlin, said: "Brand planning sits at the heart of everything we create, from strategy to innovation and design. Katie is an inspirational planning director who will provide us with visionary leadership in this area."