Morgan will be responsible for building Grey's digital strategy, strengthening its position in the market and growing business. He will work alongside Leon McComish, Grey's head of digital, and will report to the Grey chief executive, Chris Hirst.
Morgan, a former vice-chairman of the IPA Digital Creative Committee, left Elvis in October last year as the agency restructured its management line-up. He launched Spike, the digital agency within Elvis, in 2008. Before that, Morgan was the client services director at Tribal DDB, where he spearheaded Tribal's internal integration process.
He has also worked at Arc, where he was the interactive director EMEA, and Leo Burnett, where he headed the digital and integrated business across all Procter & Gamble brands.
Grey is looking to build on previous activity, for clients including Lucozade and Honda, that has run across digital channels in addition to traditional media.
Morgan said: "As agencies continue to evolve, Grey's emphasis on long ideas and open culture is an exact reflection of the values needed to excel in digital marketing. So the chance to join it and help it on its journey is exciting."