McLean takes over at PHD for Scott Hagedorn, who will head Annalect, a new digital data and analytics operation at Omnicom. At GroupM, McLean held the title of worldwide chief business development Officer.
Along with the PHD leadership post, McLean joins the Omnicom Media Group's U.S. management team, led by Page Thompson.
McLean entered the agency world as a TV buyer in the late '80s, and rose to lead the Burger King and P&G businesses at DMB&B in the U.K. He then moved to Disney, overseeing its media business.
He then shifted to Young & Rubicam, where he joined the group forming its stand-alone media unit, The Media Edge, and later helped to merge it with CIA. For about a decade, he headed client relations globally for Media Edge and its successor.
McLean, who starts his new post Dec. 1, stated that "despite all the fragmentation and change, the challenge for media agencies remains the same as it has always been -- to understand our clients' business dynamics, and define the role media plays in driving growth and a sustainable competitive advantage."