The results have led to renewed calls for more Government funding in third level institutions
All of Ireland's universities, bar one, have slipped down the international rankings.
The latest QS World University Rankings show NUI Galway has moved up 22 places to 249th in the world.
The chart of over 4,000 third level institutions puts MIT in Boston at number one, followed by Stanford and Harvard.
President of NUI Galway, Dr Jim Browne, said: “Our continued rise in world university rankings reflects the ambition, hard work and creativity of our staff and students.
"This year marks the conclusion of the major 10-year capital development programme which has transformed the NUI Galway campus, almost doubling the amount of teaching and research space," he added.
Meanwhile, the Irish Federation of University Teachers (IFUT) has said new Government initiatives and funding are required to counter any 'ongoing undermining' of Irish universities' standing internationally.
IFUT General Secretary, Mike Jennings, said: "The Government must act on commitment in the Programme for Government to implement the National Plan for Equity of Access to Higher Education (2015).
"[They must] provide adequate funds to enable universities to recover from a decade of what now seems like deliberate neglect and downgrading of third-level education."
Fianna Fail's Education spokesperson Thomas Byrne claims the results for Irish colleges are the result of years of under-investment.
"There needs to be a €100 million added extra each year until 2021 from general taxation to fund our university and third level sector," he argued.