Lewis will work alongside David Pugh Jones in developing new growth opportunities with brands and agencies.
From next month, he will report to Kate Burns, general manager of BuzzFeed Europe.
Prior to BuzzFeed, Lewis was head of platforms at Gravity Road, leading brand publishing strategies for Sainsbury's and Bacardi Global Brands, including the partnership to launch Jamie Oliver's Drinks Tube.
Before Gravity Road he was head of digital content at Shine Group, where he developed multi-platform extensions for global TV formats including MasterChef.
Burns said: "I am excited to have Digby join BuzzFeed Europe as he has understands the importance of how social content can spread on different platforms and has years of experience creating inspiring and engaging content for top brands on multi-platforms."