Exon’s promotion follows her contribution at the agency since she founded its research and development unit, BBH Labs, four years ago.
She will report directly to Ben Fennell, the chief executive of BBH London, and work closely with the chief strategy officer, Jason Gonsalves.
Exon joined BBH in 1997 and, in addition to launching BBH Labs, has led client business including British Airways, Levi’s and Johnnie Walker.
Her appointment reflects increased investment in digital from BBH, which has led to the agency creating digital work across 75 per cent of its client base, including Burberry and Unilever.
Fennell said: "This is a well-deserved promotion and part of a long-term strategy to hire and promote at the top of the company to help extend our reach and skill set."