Kennedy, who has agency and client-side experience, has been given the newly created dual role of chief strategy officer and CEO of the Southern Hemisphere.
Andrew Eyles, Blue Marlin's group managing director, said: "We are delighted to welcome such a globally respected leader onboard. Mark's strategic mind, creativity and energy will be a perfect fit with the group and will help us build our business across the world."
Kennedy said: "I am very pleased to be joining the team at Blue Marlin. I think the company is a rare jewel in the branding and design industry -- international but independent and with a unique culture that produces great work which has a real impact on client businesses and brands.
"I have known of Blue Marlin for a number of years and have been impressed by the quality and consistency of their work. They attract great clients and people and are one of the industry's most innovative and exciting businesses."
As Landor's chief strategist, Kennedy was responsible for its global brand stategy.
Before joining Landor, Kennedy worked for brewer SABMiller, where he helped launch a joint venture called CRE Beverages in India and China. He has more than 15 years' experience in advertising, design and marketing and has worked on some of the world's leading brands, including Nestle, Unilever, Pedigree Foods, Woolworth, Shell, Kodak and Levi Strauss.
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