Wallinger joins following a 10-year career at Craik Jones, where he helped develop new business at the agency with Unilever, Boots, COI, Diageo and Orange. He began his career at Rank Xerox, and also held roles at O&M Direct, BMP and Aspen Direct.
His appointment follows the launch of the agency's Loyalty Practice division last week, which is being headed up by Louise Isaacs, a former senior consultant at Dunnhumby.
It is understood Wallinger will work closely with Isaacs across the agency's data and loyalty offerings.
The agency said the new division will help it develop consultancy services in data and loyalty marketing, alongside its core account planning, digital and creative work.
Wallinger said: "Hicklin Slade & Partners has taken a long hard look at its offering and established that the way to meet the client challenges of the future is to place measurability, accountability and insight at the forefront of everything.
"That sits perfectly with the way I view the challenge. I don't see myself as a statistician or an IT expert - rather a marketer who understands how data, offline and online and multi channel, should guide truly creative relationship marketing."