The Society of St Vincent de Paul has launched an urgent fundraising appeal, as it expects calls for help to increase in the coming weeks.
It said many families were struggling to pay food and energy bills due to loss of income from the coronavirus outbreak.
St Vincent de Paul has been helping families in need for more than 175 years and last year gave support to more than 160,000 people in Ireland.
Now, during the coronavirus outbreak, it says things are as difficult as they have been for 20 years, with thousands struggling financially.
The society is seeking public support with an urgent appeal for funds - saying its income is drastically reduced from the closure of its 234 shops and the cancellation of collections.
National President Kieran Stafford said low income families have become "no income families" overnight, as they wait for State supports to come through.
And calls to their helpline are at their highest level since the crash in 2008, with people seeking help paying food and energy bills.
SVP is asking the public to donate online and is also calling for volunteers as they expect to be even busier once lockdown restrictions are eased.