Vaughan-Thomas joined the agency this week from asset-management specialist consultancy Peregrine Communications, where he had been a partner and executive director since 2006.
At Broadgate Mainland, he will work with directors Roland Cross and Mark Knight to drive new business and enhance its client offering.
Vaughan-Thomas said he would continue to focus on the asset management sector, but that the more general financial services and professional services focus of Broadgate was a significant factor behind his move.
He added that one of his key roles would be to raise the profile of the agency in the market, commenting: 'I think most would agree that Broadgate has a lower profile than it should have considering the scale of the business, so we want the company to become better known by more clients and to enhance our external messaging.'
Broadgate Mainland has a huge opportunity to grow its presence in the specialist financial services space, according to Vaughan-Thomas, given that recent agency consolidation has resulted in fewer direct rivals, while others have changed their offering.
Before joining Peregrine, Vaughan-Thomas was head of group comms for asset management firm Keydata Investment Services since 2000.
Before this he held senior positions at both Quill Communications and Citigate Dewe Rogerson.
Cross said: 'We are committed to growing the business at all levels and a senior professional of Roddi's calibre is a great addition to the team. His technical knowledge and programme development skills will have an immediate and positive impact.'