Currently comms director at travel money firm Travelex, a role she has held for the past five years, Filer will be based at Dentsu Aegis' global HQ in London, and report to chief executive Jerry Buhlmann.
In her new role Dani will have strategic responsibility for promoting and developing the agency brands of Dentsu Aegis, its products, services and its executives, as well as communicating with stakeholders throughout the network.
Before working at Travelex, Filer was associate director at Ogilvy PR in Australia, responsible for key global FMCG clients, and she previously held senior strategic positions at Accenture.
Buhlmann said: "With ambitious plans and opportunities ahead of us, Dani is joining the business at a critical time and we’re looking forward to leveraging her portfolio of established communication skills to further articulate to all our stakeholders how Dentsu Aegis is different and better."
Filer said she was "looking forward to working with the team to further evolve the brands and culture, which in turn will help our clients achieve their business ambitions".
Dentsu Aegis Network has 27,000 staff working in 123 countries across more than 60 individual brands – and has made several acquisitions this year.