The Christmas bonus is being paid out to over 1.2 million social welfare recipients this week at a total cost of €219m euro.
Payments will be made to pensioners, people with disabilities, carers, lone parents, long-term unemployed people and many other recipients.
Some of the homeless will be among them.
Dermot Kirwan, a volunteer with the Morning Star Hostel in Dublin's North Inner City, says the cost of being homeless is greater than you might think, and the Christmas bonus can literally be a life-saver.
"Being on the streets during the day is a very expensive way of living," he said.
"You can't cook your own food. You're either buying cooked food, you try to stay warm - there's only so long you can stay in a library, and it's not advisable to be in a pub all day - so you're spending money. It's costly.
"For homeless people, and a homeless man in particular, the Christmas bonus is very much appreciated."