Almost 16,800 people sought help from the Simon Communities of Ireland last year.
That's a 26 percent increase on the previous 12 months.
The 2018 annual report for the homeless charity shows 5,263 people accessed its housing supports, that's a 57 percent rise on 2017.
The numbers accessing emergency accommodation also increased by 80 percent to 1,738.
Simon Communties of Ireland spokesperson Wayne Stanley says it shows the scale of the crisis and the challenge groups face:
"In particular they showed the huge efforts that the Simon Communities are making to try and keep people in their homes they have or to try to find a new home and prevent them from entering homelessness in the first place"
He went on to say that this work is intensifying because of the shortage and sometimes absences of affordable homes across the country.
It comes as the numbers in emergency accommodation reach record levels.
Figures from the Department of Housing for October, which were released this week, show 10,514 people are now officially homeless.