The institution was created in 1975, on an ad hoc basis, and on 18 June that year Dr Danny O'Hare was made acting director of the institution, and a day later the first governing body met. It was intended at this stage that the institution become the unified structure under which the colleges of what later became Dublin Institute of Technology would unite, but by 1978 it became apparent that this would not be the case and instead an independent institution developed with a distinct identity and mission.
Ultimately the title "Dublin City University" was chosen and this was confirmed by the Dublin City University Act of 1989.
The early focus of the institution was, in particular, on science and technology, although it has also had, and has, a large business school. It has recently developed a presence also in the performing arts and in the humanities.
DCU has been providing adults all over Ireland (and abroad) with flexible access to higher education for over thirty five years. In 1982 the National Distance Education Centre was located at DCU and for many years offered programmes in the traditional ‘distance education’ mode of delivery. It changed to Oscail – DCU Online Education in 2004 to reflect the reality that its programmes were increasingly designed with large elements of online support.
As of 2015 there are almost 55,000 graduates of Dublin City University.