The school is being moved making the site surplus to defence requirements and available for development.
South Bucks District Council wants to see a high-quality residentially-led mixed-use development scheme on the site.
The DIO has agreed a working partnership with Inland Homes which owns land adjacent to the site that is needed to deliver access.
Martin Lloyd, DIO Head of Disposals South, said: “Future development of the Wilton Park site in Beaconsfield supports the Government’s housing agenda in providing brownfield land for much-needed market and affordable housing.
“DIO is pleased to be working with Inland Homes and the local planning authorities to deliver a development brief for the site”
Paul Brett, Land Director of Inland Homes, said: “Inland are delighted to be working with DIO, South Bucks District Council and Buckinghamshire County Council to formulate the development brief on this very important project.
“As highly experienced developers with particular expertise in creating new communities on challenging sites, we are looking forward to creating a very special new community that integrates well with its sensitive surroundings.”
Roger Reed, Portfolio Holder for Sustainable Development at South Bucks District Council, said: “Wilton Park is an important opportunity site where the District Council will be seeking a – high quality – mix of residential and employment development, community facilities and open space.
“The planning policies in the Council’s recently adopted Core Strategy provide a broad framework for redevelopment of Wilton Park, and the next stage in the process is to prepare a development brief that will establish the more detailed development and design principles for this key site.”