The start-up will be based in MCBD's Rathbone Place office in London and will be run by the former Claydon Heeley Jones Mason managing director, Mark Leversedge, and the former Inferno client services director, Martin Semmens.
Elvis launches with three clients already on board.
Two of them, P&O Cruises and Radio Times, are shared accounts with MCDB, while the third, Mitchell & Butlers' pub brand O'Neills, is unique to Elvis.
The agency will specialise in direct marketing, customer relationship management, sales promotion and digital media. It will also offer its clients brand, media and research planning through its partnership with MCBD.
Elvis's creative department will be led by John Treacy and Dan Colley, the award-winning team that is joining from Archibald Ingall Stretton.
The start-up will aim to get its creative department involved with clients as early as possible. "We don't believe in hiding the creatives in the back office," Leversedge explained. But while Elvis will position itself as creatively led, the agency's managing partners dismiss terms such as "boutique" or "hotshop".
Semmens said: "We combine the speed of a start-up with the strength of a substantial agency to help our clients outmanoeuvre and outmuscle the competition. Our aim is for Elvis to bring new energy to the marketing and give clients a fresh alternative."
Jeremy Miles, the chairman of MCBD, added: "We are delighted to back Elvis. It's another step towards offering clients a total through-the-line communications service. We have great confidence in Elvis' future."