Technological University Dublin (Irish: Ollscoil Teicneolaíochta Bhaile Átha Cliath) or TU Dublin is Ireland's first technological university. It was established on 1 January 2019, with a history going back to 1887 through the amalgamated Dublin Institute of Technology which progressed from the first technical education institution in Ireland, the City of Dublin Technical Schools. It is the second-largest third-level institution in Ireland, with a student population of 28,500.

The university was formed by the amalgamation of three existing institutes of technology in the Dublin area – Dublin Institute of Technology, Institute of Technology, Blanchardstown, and Institute of Technology, Tallaght, taking over all functions and operations of these institutions. It is the eighth university in Ireland, and the fourth in County Dublin. The university asserts an entrepreneurial ethos and industry-focused approach, with extensive collaboration with industry for research and teaching. The flagship campus is in Grangegorman, Dublin, with two other long-term campuses, in Tallaght and Blanchardstown, and remaining legacy sites at Bolton Street and Aungier Street.

TU Dublin has approximately 2,700 full-time staff. Dr Deirdre Lillis became President of the university in January 2025.

TU Dublin has its origins in the City of Dublin Technical Schools, with a Technical College founded at Kevin Street in 1887 by poet, songwriter and novelist Arnold Felix Graves. In 1978, with the formal amalgamation of the College of Technology, Kevin Street, and five other specialised colleges in Dublin under a federalised arrangement, the Dublin Institute of Technology was formed.

From 1976 to 1998, the Institute of Technology had a relationship with the University of Dublin, the degree-awarding body for Trinity College Dublin, for the sharing of facilities, equipment and staff, joint research seed funding, research partnerships, and for the University of Dublin to award Dublin Institute of Technology degrees under their own name in return for academic oversight; this partnership was credited for a 22 times increase in research output in the Institute of Technology in 1992 compared to 1975, and a significant increase in the institute's status. With the improved status, staff experience from the partnership, increased course demand, and success of Dublin Institute of Technology graduates in employment compared to university graduates, politicians and university academics sought greater autonomy for the institute, with Fine Gael higher-education spokesperson Theresa Ahearn saying "The colleges, in particular the DIT, at this stage rightly claim to have long experience of teaching to degree level ... I suggest that now is the time to give the colleges this power to award their own degrees". On 10 July 1992, Minister for Education Séamus Brennan stated that "The DIT will be given degree awarding powers", and these powers were ultimately granted in 1998 under the Dublin Institute of Technology Act, 1992.

Institute of Technology Tallaght was established in 1992, at its dissolution offering courses through the School of Business & Humanities, the School of Engineering, and the School of Science & Computing.

Institute of Technology Blanchardstown was established in 1999, and at its dissolution offered courses through the School of Business, the School of Humanities, and the School of Informatics and Engineering.

In 2014, the Dublin Institute of Technology (DIT), Institute of Technology, Blanchardstown (ITB) and Institute of Technology, Tallaght (ITT) jointly entered into a formal process to seek to merge into a university. At the time, following the Institutes of Technology Act 2006, there were fourteen IT's in Ireland, and a political appetite emerged to amalgamate several to form a more advanced third-level institution, known as a technological university, similar to that of Delft and other technological universities in Europe.