In the newly created position, Whitson will work on strategic output for communications, data, digital and user experience.
Whitson’s remit will also include "forging even closer ties" with other agencies in McCann Worldgroup.
He will begin his new role in August and report to Debbie Smith, the chief executive of MRM Meteorite.
Smith said: "Chris really gets the role of strategy in a multidisciplinary agency and has a real passion for driving powerful insights into great creative work.
"His appointment will further strengthen the agency’s ability to deliver truly meaningful connections between our clients’ brands and their customers."
At WPP, Whitson was responsible for strategy for Team News, WPP’s dedicated combined shop for News UK that incorporates Grey and Wunderman.