The firm has also promoted Ben Miles to design director and Joao Peres to senior designer.
According to Interbrands managing director, Richard Curtis, these new appointments follows a year of "significant growth".
Nash joins from S&C where he was a strategic design consultant. His career has focused on user-centred insight and experiential design and his client roster has included Electrolux, McDonald's, Westpac and Vogue.
Nash's background in product and service design and innovation will "play a key role in evolving Interbrand's strategic product ahead of the competition", commented Curtis.
Cambridge graduate Rebecca Lester, moved to Australia at the start of the year and has been an account manager with The Leading Edge where she worked with clients such as Kraft Foods, Cadbury, KFC and David Jones.
Miles's promotion is on the strength of his work with Telstra's rebrand and AGDA (Australian Graphic Design Association), commented Curtis. While Peres' career highlights also include his involvement with Telstra's rebrand as well as his work on the the launch of Alzheimer’s Australia's campaign.