The John McIntyre Conference Centre now has capacity for 350 delegates theatre-style, with four breakout rooms, two boardrooms, a lounge area and an open-air terrace. A 650-seat restaurant, with adjoining bar and lounge, has also been added.
Edinburgh First, the university's conference, catering and events operation, hopes to attract more business to the expanded venue.
Edinburgh First assistant director of business development Chris Barnes said: "We believe that the new facilities will help us persuade increasing numbers if businesses to host their events in Edinburgh. Business tourism such as this is worth an estimated £300m to Edinburgh and the Lothians each year, and we are confident this investment will help increase our share of this valuable market."