Beaton has been director of information at the Met for five years and is responsible for providing all information, communication and technology services to the force's 45,000 police officers and staff.
The move came shortly after Ian Blair took up the position of police commissioner at the Met.
Beaton said, "The appointment of the director of information to the Met's management board is a significant step forward - and tangible proof of the strategic importance of information and communications to the service.
"We are continually developing and delivering policies and processes that enable our officers and staff to find new ways to manage and communicate information that will add value to investigations and improve the use of resources."
Beaton also has a seat on the Police IT Organisation board and on its Airwave and national management information system programme boards.
Before she joined the Met, Beaton's experience in IT included time as chief information officer at ICL, a senior partner with PA Consulting Group and consultancy for the NHS and central government.