Trinity College is closing its on campus accommodation after at least eight students attending the college tested positive for Covid-19.
The university has told all students living on campus that they must leave, unless they are self-isolating or will experience homelessness or another great difficulty as a result.
In what it said was "one of the most difficult decisions to date" the college said that based on medical advice regarding the health and safety of students all residents on campus, in Trinity Hall, the Binary Hub, and Kavanagh Court must now leave.
The college says that as well as the at least eight cases, "many more students and staff are self-isolating".
The students have been given until 8pm tomorrow to leave.
The college says that students with a home overseas should aim to have left their Trinity accommodation by 5pm on Wednesday.
It says the decision has been taken because large, highly concentrated numbers of students living on campus will increase the chance of rapid transmission of the coronavirus.
It says its capacity to quarantine those who are sick and those who have been exposed is extremely limited.
Trinity College says that any student who has the virus or is currently self-isolating can remain living on campus, as can any student who faces homelessness, or whose family has the virus, or who has immigration or travel restrictions, as well as any student whose family lives in an area with extremely limited internet connectivity.
Any PhD student who must conduct lab or other research on campus that's required for their thesis is also allowed to stay.
Those students are being asked to register for permission to remain.
An email sent to staff by Provost Patrick Prendergast states; "We know it will be difficult for some of you but the situation is serious and it is vital to take drastic action now for your own safety and well-being".
Around 2,400 students live in the residences affected. But it is believed that many have already left their accommodation to return to family homes.
Trinity Hall is located on Dartry Road in the south Dublin suburbs. Kavanagh Court is on Gardiner St in the city centre. Binary Hub is located on Thomas St.