A total of 550 children per month received support from a dedicated domestic violence service from September to December last year.
That is according to a report by the national social change agency Safe Ireland, which works with 39 domestic violence services nationwide.
Based on data collected by 30 services, the report shows that of the children who accessed services in the latter part of the year, at least 486 of them had never accessed a service before.
The report - 'Tracking the Shadow Pandemic - Lockdown 2' - also shows that at least 265 children stayed in a range of domestic violence accommodation every month between September and December.
Over this period, 167 women on average every month were staying in refuge, safe and supported housing.
Safe Ireland said the high number of children that accessed a range of specialist support services in the month of December, and in the run-up to Christmas, is of particular concern.
While the numbers of women accessing services reduced in December, it said the number of children being supported by domestic violence services rose to 604, the highest point in the year of the pandemic.
Safe Ireland Chief Executive Mary McDermott described children as "the invisible victims of this shadow pandemic of violence and abuse" and said they must be identified as victims in their own right.