Rhodes replaces Chris Seth, who left last year to become the managing director of Richmond Events. She joins after a two-year spell as a consultant, during which time she worked at Proximity.
In her new role, Rhodes' responsibilities will include running the department of nine and building the number of clients it works on independently, as well as providing media services to Proximity clients such as Save the Children, the RNLI, Shell and Sainbury's To You. She will also oversee channel strategy for the agency's clients.
During her 20-year career, Rhodes has worked in media above and below the line. She was a founder of Starcom Motive Direct and managing director of MediaCom Direct. She also worked at WWAV Rapp Collins and OMD.
Rhodes said: "There is a need in the market for communications specialists that can drive the channel strategy, plan and buy the media and then track and analyse a client's investment effectively and continuously."