The number of people in emergency accommodation increased by 234 people last month, with the total number just under 10,000.
The latest homeless figures released by the Department of Housing show 9,987 people were in emergency accommodation in January - a new record high.
That breaks down as 6,363 adults and 3,624 children.
The latest figures compare to 9,753 people in December.
"Very difficult situation"
Housing Minister Eoghan Murphy admitted the increase was 'disappointing'.
He said: "We remain in a very difficult situation where homelessness is heavily impacting on the lives of families and individuals.
"There was a decrease of people in emergency accommodation in December, which we understood at the time to be partly due to seasonal reasons, and so an increase in January was anticipated but that doesn’t mean it is acceptable."
The figures show a slight decrease in the number of homeless families - down three compared to the previous month.
There was also a decrease of 32 families accommodated in hotels in Dublin.