The unit will be run by Neil Kleiner, who joins the agency from its parent group, Havas Media, where he was the UK head of social media.
Kleiner will oversee a team of six but look to expand the unit. He will report to the AIS management team of Sarah Stratford, the strategy director, Geoff Gower, the creative director, and Stephen Watford, the commercial director.
The division will work for clients including Skoda, EDF Energy and CoppaFeel!
Kleiner said the division's launch was based on clients' needs, with more wanting specialists overseeing their social media strategies. It will also work alongside the agency's technical, creative and strategy departments to provide "creative innovation".
Stratford said: "Having worked with Neil for the past two years, we know he'll be a huge asset to our team."