Of today's figures, Dublin recorded the highest increase of 218, while there were 63 in Cork, 60 in Donegal, 35 in Galway and 31 in Kildare.
The remaining 204 cases were located across 21 additional counties.
Speaking at today's press briefing, Dr Ronan Glynn confirmed that 156 people are currently being treated for Covid-19 in Irish hospitals, 25 of whom are in Intensive Care Units.
Professor Phillip Nolan added that the average number of cases being confirmed each day is now 468, while our five-day average is 509 cases. The 14-day incidence rate per 100,000 in the Republic is now 124.
Prof Nolan also said that the daily positivity rate has now increased to 4.3 per cent, saying the country is showing an exponential trend in cases.
He also estimated the reproductive rate of the virus is currently about 1.2. The reproductive rate represents the average number of people a case of Covid-19 will pass the virus on to- with a figure under 1 showing the virus is being supressed.
Chief Medical Officer Dr Tony Holohan led the briefing, his first since taking leave for family reasons. He began the briefing by thanking his colleagues in Nphet, particularly Dr Glynn, thanking him and his family.
He also said that the air has been cleared between himself and Tánaiste Leo Varadkar after the later criticised Nphet's decision to recommend Level 5 restrictions in an interview with Claire Byrne on Monday night.
Earlier today, major traffic congestion was caused nationwide as gardaí set up checkpoints to encourage public compliance with new Level 3 restrictions to curb the spread of Covid-19.
More than 2,500 Garda members are set to be deployed as part of a policing surge across the Republic.
In the North, 828 cases of Covid-19 were notified today, with one additional death due to the virus.