Munro will be responsible for securing new clients, promoting the firm's profile and managing staff and client relationships, said MD Chris Whitehouse, to whom she reports.
He said Munro would focus particularly on winning business in the environment and education sectors.
Munro said a main challenge in her new job was ensuring the agency differentiated itself from other public affairs offerings.
The agency has also promoted former YMCA parliamentary officer David Hare to account director. He joined last year as an account executive.