Rayman, who is the integrated strategy director on DDB's Volkswagen business, will join Adam & Eve at the end of this month.
He will report directly to the agency's strategy partner, David Golding, and will work across its entire portfolio.
Rayman began his career in advertising in 2000 at the CRM consultancy Zalpha, which was then part of Rapp.
He moved to DDB London in 2005 as a planner, working on Volkswagen, Anheuser Busch and Dell.
In 2008, he left the agency to join the PR agency Weber Shandwick as strategy director for EMEA, but rejoined DDB a year later to oversee planning on VW.
Since his return, Rayman has led the strategy on VW's "unbelievable value" campaign, which uses humour to counter the view that VW vehicles don't offer good value for money.
He has also helped launch DDB's Social Media unit, which played a major role in the agency's successful pitch for the integrated Virgin Media account last year.
Rayman's departure follows that of Sarah Watson, DDB UK's head of planning, who announced earlier this month that she was leaving to join Bartle Bogle Hegarty in New York.
Golding said: "Leo is a rare talent, and his skills and experience will grow our planning capabilities considerably."