The number of people in emergency accommodation across the country reached almost 11,000 last month, which is the highest number ever recorded.
New figures released by the Department of Housing show there were 10,975 people in emergency accommodation in September, a 1.6% increase on the previous month.
The Monthly Homeless Report for September shows there were 7,633 adults and 1,532 families accessing emergency accommodation in the month, including 3,342 children.
The Simon Communities of Ireland have described the numbers as "shocking" while Depaul said it was "saddened".
Minister for Housing, Local Government and Heritage, Darragh O'Brien said "the situation is very challenging".
In a statement, he said: "Fully aware of the risks of homelessness faced by renters this coming winter, the Government has just legislated to protect renters who are facing homelessness by deferring any 'no fault’ tenancy terminations from taking place this winter.
"While this emergency measure is necessary and will provide assistance in the short-term, the long-term answer to our accommodation challenges, including combating homelessness, remains an increased and sustainable supply of new housing."
Focus Ireland CEO Pat Dennigan said: "While a no-fault eviction ban is necessary, what is also crucial is what the Minister for Housing will do for the five months while the ban is in place to tackle the underlying problem.
"We need measures to radically ramp up and accelerate delivery of social and affordable housing, meaningful policies and resources deployed to tackle vacancy, and a suite of measures to incentivise landlords to stay in the market.
"We must avoid a repeat of what followed after the previous eviction ban during the Covid-19 lockdowns which saw a dramatic increase in homelessness when the measure was lifted."