Lembke will be the first executive creative director at the agency since it was founded in 1991. The creative heads Rebecca Rae, Mark Buckingham and David Brown will all report to Lembke.
Lembke currently holds the position of creative director and partner at the Stockholm-based Otto, part of BBDO's Proximity network.
Since setting up the agency seven years ago with the founding partners, Stefan Petterssonand Per Ottosson, Lembke has worked on accounts including Procter & Gamble Worldwide, DaimlerChrysler, Masterfoods and Shell. His career has also included a stint at the Swedish business-to-business agency Sandberg & Co.
Lembke said: "As well as a great record in delivering big ideas, Craik Jones has the clients, the talent and the genuine understanding of the challenges it faces. I'm very excited to be joining at this point in the agency's history."
Scott added: "We're thrilled to have appointed Jonas. We've spoken to a lot of extremely talented people in the past few months, but he impressed us enormously from the outset. He places digital at the heart of his thinking, which is central to our business and creative strategy."