The inquiry explored how government bodies and the ADF responded to high rates of suicide and suicidal behaviour among active members and veterans.
Evidence provided in the four-week hearing explored the nature of the cultural and systemic issues that led to the failures.
"History will absolutely judge those who are in a position to make a difference," commission chair Nick Kaldas said.
Witnesses gave "heartbreaking and, at times, harrowing accounts" of experiences of suicide and suicidality and how they or loved ones were "let down by the organisation they had sworn to defend."
The chair echoed the words of Defence Minister Richard Marles who told the inquiry on March 7 that "history will be our judge".
"We hope this commission has been the much-needed shock to the system that will inspire the change required to address the national tragedy of defence and veteran suicide once and for all," Mr Kaldas said.
Chief of the ADF Angus Campbell at The Royal Commission into Defence and Veteran Suicide. (HANDOUT/ROYAL COMMISSION INTO DEFENCE AND VETERAN SUICIDE)
The final hearing on Thursday concluded with the chief of the Australian Defence Force General Angus Campbell apologising "unreservedly" for the shortcomings of the military.
"Defence is committed and I am committed to doing better," he said.
The royal commission will have a ceremonial closing at the State Library of NSW on August 28.
A final report is due by September.
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