The ISPCC says children are being harmed because social media companies are not being properly regulated.
Facebook and Google are among the companies appearing before the Oireachtas Communications Committee this afternoon.
It is discussing a proposal to introduce a Digital Safety Commissioner to regulate harmful content found online.
In his opening statement, CEO of the ISPCC John Church says a regulatory body in some form is needed.
"Not long after the launch of the action plan, and indeed in recent times, the public has been presented with stark examples of where self-regulation is falling," said Mr Church.
"It is our experience that these failures can impact negatively on children and that there are positives actions that Ireland can take to better protect children online."
You can watch the committee proceedings live here: