Munds, who reports to the planning partner Simon Clemmow, will work across several accounts, including the recently won British Gas account.
Munds began her career at TBWA\London before moving to Lowe Howard-Spink where she worked on the Reebok and Vauxhall accounts. This was followed by a spell at TBWA\Chiat\Day.
On joining M&C Saatchi, Munds initially worked on the British Airways and Scottish Courage accounts. She has latterly planned campaigns for the agency's Inland Revenue and NatWest clients.
Clemmow said: "Hiring Rebecca is another example of our policy of getting the best people in London under one roof."
Munds' appointment follows a spate of new-business wins for CHI this year. Last month, Butcher's Pet Care consolidated its advertising business into the agency. This followed the win of the Anchor Butter account.