Health officials say 430 more people have tested positive for COVID-19 in the Republic - the highest number of cases reported in a day since April.
No further deaths have been recorded.
Some 212 of today's cases are in Dublin, 54 in Cork, and 23 in both Donegal and Galway.
The Acting Chief medical Officer Dr Ronan Glynn has urged people to "play their part" and cut their contacts, adding "we have absolutely no room for complacency".
It comes after the HSE Chief Executive Paul Reid issued a “call to arms” and warned that the impact of COVID-19 on Irish hospitals is now “as significant” as it was at the peak of the outbreak.
He said there are now 110 COVID-19 patients in Irish hospitals with 18 in intensive care.
We've now 110 #COVID19 hospital cases,18 in ICU. Although lower than our worst peak, the impact on our hospitals is as significant as we're now trying to keep all of our other services running too. This is a call to arms to everyone to get right behind all that we ask. @HSELive
— Paul Reid (@paulreiddublin) September 27, 2020
He noted that although the figures are lower than at the “worst peak” the impact on Ireland’s hospitals is “as significant as we're now trying to keep all of our other services running too.”
“This is a call to arms to everyone to get right behind all that we ask,” he said.
Meanwhile, the Chair of the COVID-19 Expert Advisory Group Dr Cillian De Gascun said Ireland’s testing capacity may be increased over the winter if cases continue to rise.
He also rejected claims the system was returning high numbers of false positives – noting that it delivers a maximum of one false positive for every 500 tests.
Meanwhile, 187 people tested positive for the virus in Northern Ireland in the past 24 hours.
DCU professor Anthony Staines called for an all-island approach to the coronavirus outbreak.
“The two Governments have a long tradition of cooperating on healthcare,” he said.
“It is a challenge for all sorts of reasons, not least Brexit but I think the willingness in the North is there to take serious drastic actions against their rate of infections and it is the same in the south.”
He said that “if we work together, we are more effective.”