Mr Hill joins three other independent MKDP board members: former Commission for New Towns chief executive and MKDC planning director John Walker, businessman Bob Green and chair John Duggan.
The council is represented by council leader Cllr Andrew Geary and Cllrs Norman Miles, Edith Bald and Cec Tallack.
The board has also appointed Charles Macdonald, partner of property consultants Bidwells, as chief executive.
Mr Duggan, a former chairman of developer Gazeley, said: “We were very pleased to be able to appoint Bob. His knowledge and range of professional property experience will be invaluable to the board.”
MKDP is continuing its search for a fourth independent board member, he added.
Mr Hill has run his own property consultancy since 1998 after four years as property director of Railtrack plc. He left MKDC in 1992 to become managing director of the British Rail Property Board.
He has also worked with Milton Keynes Parks Trust, the Milton Keynes Community Foundation and with the city’s theatre and orchestra. He is a director of the local Citizen’s Advice Bureau.