In the new role, Robertson will be responsible for driving the agency’s comms planning work. He will report to Stuart Smith, Anomaly’s chief strategy officer and partner.
At BBH, Robertson worked on accounts including The Guardian, Johnnie Walker, Axe and Google.
Anomaly picked up Johnnie Walker’s global ad account in December 2014.
Before BBH, Robertson worked at Wieden & Kennedy. He started his career in media at PHD and then Carat, where he rose to strategy director before leaving in 2010 to work at Dare.
Camilla Harrisson, the chief executive and partner at Anomaly London, joined from M&C Saatchi in November. She said: "Communications planning is key to the Anomaly proposition, which was created specifically for a world where change has wreaked havoc with budgets and businesses, and rendered traditional models obsolete.
"In a world where the line between media and creative has blurred like never before, Simon is perfect for this role, possessing both the intelligence and fearlessness to ask the right questions – and the skills and expertise to answer them."