"The commission was not only a beacon of light and truth but it has been the harbinger of real change," president Dr Cathy Kezelman said.
Ms Gillard announced the creation of the commission in 2012.
The inquiry, which ran from 2013 - 2017, examined the history of abuse in religious groups, educational institutions, sporting organisations, state institutions and youth organisations.
It received more than 40,000 phone calls, 25,000 letters and emails and held about 8000 private sessions, resulting in 2575 referrals to authorities, including police.
"There is still a long way to go for the needs of all survivors to be met but without the catalyst of the Royal Commission and Ms Gillard's leadership, the voices of survivors would still not be heard, and the culture of secrecy, stigma and cover-up would continue unabated," Dr Kezelman said.
"The standing ovation Ms Gillard received from survivors at the recent National Apology in October said it all," she said, referring to Prime Minister Scott Morrison's recent apology.
According to the organisation, an estimated five million Australian adults experienced trauma and abuse in their childhoods.
"Research shows that with the right support, adults who have experienced childhood trauma and abuse can and do recover," material from the organisation says.
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