12,441 people were registered as homeless in May.
In April, it was 12,259, including 3,594 children.
The Housing Minister Darragh O'Brien says he's "disappointed".
However he has welcomed the fact that the increase is less than the figures seen over the past two months.
But Minister O'Brien says that'll be of no comfort to those directly impacted.
Catherine Kenny, CEO of Dublin Simon Community: "There were 9,160 people in emergency accommodation in Dublin in May, representing a 23% increase over the past 12 months.
"As we revealed earlier this week, on one night in June, 25% of Dublin Simon’s emergency beds were occupied by workers. They were cleaners, event and retail security staff, taxi drivers, van drivers and lorry drivers, scaffolders, electricians and construction workers, healthcare assistants and carers, shop workers and retail staff, barbers and bar workers.
"With the scarcity of suitable accommodation, soaring rents, the cost-of-living crisis, and notices to quit coming to the end of their term, housing insecurity is affecting workers like never before.
"The lack of exits from homelessness into accommodation also means that people are becoming stuck in homeless services indefinitely, exacerbating the bottleneck in the system and creating distress for the individuals affected.
"We need fully resourced tenancy sustainment services, homelessness prevention teams to be established in each local authority, and a review of Housing Assistance Payment (HAP) to reflect market rates, to occur in conjunction with the longer-term plan to increase housing supply.
"Moreover, we are calling on Government to deliver sustained funding for the homelessness sector that reflects the full cost of service provision, accounts for the extraordinary surge in need, and appropriately remunerates our trained professional staff who are working at and beyond capacity."