He will share the title with Alistair Bryan, who has been promoted to the role from his previous job as Euro RSCG's board account director.
Boyd left Euro RSCG in 2004 to establish a sports equipment retailer.
He also led BBDO's Wireless Works study into the impact of digital technology on consumers and the potential of mobile devices as brand communications tools.
He previously worked for DMB&B as a client services director and the head of operations, before joining Partners BDDH in the summer of 2003. The agency then merged with Euro RSCG Wnek Gosper to form Euro RSCG London. His early career included spells at BMP DDB and Bartle Bogle Hegarty, and BDDP in Paris.
Bryan joined AIS in 2003 from Craik Jones Watson Mitchell Voelkel, where he was the specialist account director. He previously worked at GGT Direct, Lowe Direct and Limbo, BBH's now-defunct DM agency.
The creation of the joint roles was designed to allow the agency's partners, Stuart Archibald, Jon Ingall and Steve Stretton, to concentrate more on strategy.
Ingall said: "Boyd will bring experience, leadership and strategic ability to the account management team. Bryan has impressed everyone in the two years he has spent with us and this role reflects the work he's delivered for our clients. The two should complement each other perfectly."