The University was founded in 1845 as Queen's College Galway. It was one of the three Queen's Colleges founded under the Queen's Colleges (Ireland) Act, 1845, the others being located in Belfast and Cork. The College opened for students on 30th October 1849.By the Irish Universities Act (1908), Queen's College Galway became a Constituent College of the new National University of Ireland, and under a new Charter the name of the College was changed to University College, Galway.
In 1929, the College was given a special statutory responsibility under the University College Galway Act in respect of the use of the Irish language as a working language in the College.
Under the Universities Act, 1997, University College, Galway was reconstituted as a University, under the name of Ollscoil na hÉireann, Gaillimh / National University of Ireland, Galway, and became a Constituent University of the National University of Ireland (together with NUI Dublin, NUI Cork and NUI Maynooth).
Since the 1960's the University has experienced significant and continuous growth, both in its stock of buildings, facilities and physical resources and also in the numbers of its students and staff. Its total student enrolment during 2004/2005 academic year was over 15,000 (including students from over 40 countries), with academically strong programmes of teaching and research throughout its seven Faculties, namley Arts, Science, Commerce, Engineering, Celtic Studies, Medicine & Health Sciences, and Law.