More than 13,500 people were living in emergency accommodation in November.
It includes a record 4,105 children who faced into Christmas without a home.
Figures released by the Department of Housing today show that the number of men, women and children in homelessness reached 13,514 in November.
The latest figures show an increase of 1,972 people - or 17% - in emergency accommodation in the 12 months since November 2022.
The Simon Communities of Ireland has expressed 'deep concern' that these levels of homelessness will continue to grow in 2024 if more solutions are not delivered.
'Suffering demands action'
Simon Communities Executive Director Wayne Stanley said the numbers are 'shocking'.
"This shocking level of homelessness documented in the figures released today must be placed into context," he said.
"Each of the men, women, and 4,105 children that these figures represent are experiencing a preventable trauma.
"That level of suffering demands action. We know that the primary solution to homelessness is a home.
"Up to very recently, Governments have been heavily reliant on the private rental market to address social housing need.
"There are a multitude of reports that outline the difficulty of finding a home in the private rental market including our own Locked Out Of The Market report.
"This is no longer a viable answer to homelessness at the scale that we see today."
Mr Stanley said addressing the current crisis means Government will have to work with local authorities "to ensure more secure affordable homes are made available to those in homelessness."
He also called for increased delivery of social housing in the years ahead.
The figures show just over half of those in emergency accomodation are Irish citizens.
The rest are made up of EEA, UK or non-EEA nationals.
