Griffin moves from his position as a director at Naked next month. He will support Tim Allnutt, the founding partner of the agency, with a brief to help grow the four-year-old business.
His appointment follows recent new-business wins including Full Tilt Poker and Heyday. Naked Inside also retained the £8 million Telegraph Group account last year after a pitch.
Griffin - a Campaign Face to Watch in 2000 - joined Naked in 2004 as a senior strategist on Boots. The move reunited him with the former Rocket managing director John Harlow, one of Naked's founding partners. Griffin has also worked at Sky, where he was the media controller.
Allnutt said: "We need to invest at a senior level to help us grow the business and further enhance our offering for our clients. This is great news for Naked Inside and CHI, and is a sign of our continued growth and success as we enter our third year. Andy has loads of experience and is a brilliant bloke too, so he'll fit into the culture here easily."