Chief of Defence General Angus Campbell will have his term extended by two years despite being due to end his time in the top job in July.
Vice Chief of the Defence Force David Johnston and Chief of Joint Operations Greg Bilton will also have their terms extended by another two years.
Mark Hammond will become Chief of Navy, Simon Stuart Chief of Army and Robert Chipman will become Chief of Air Force.
General Campbell was appointed as Chief of the Defence Force in 2018 by former prime minister Malcolm Turnbull, replacing Air Chief Marshal Mark Binskin.
The last time a Defence chief had their term extended was back in 2008, when the Rudd government decided to reappoint Angus Houston for a further three years.
Defence Minister Richard Marles announced the appointments and said while there had been improvements in the diversity of ADF staff, more work was needed to boost the number of women in senior levels of the military.
He insisted the men appointed were the best people to lead the Defence Force.
"The decisions have been made against the backdrop of who we believe are the most capable people to fill these roles," he said.
Vice Admiral Johnston had been considered the frontrunner to replace General Campbell.
He would have become the first serviceman from the navy to lead the ADF in more than two decades.
New government sticks with Coalition citation stance
In 2020, General Campbell recommended a meritorious unit citation be revoked for the Special Operations Task Group, in the wake of the Inspector-General of the ADF's report into war crimes.
General Campbell announced the move while handing down the explosive report, which found evidence Australian special forces may have murdered at least 39 prisoners and civilians during the Afghanistan war.
But when Peter Dutton became the defence minister in 2021, he overturned the decision, which affected about 3,000 personnel who served between 2007 and 2013.
"It is not our intention to go over those decisions," Mr Marles said on Tuesday.
Editor's note July 6, 2022: This story was updated on 6 July to clarify the findings of the Inspector General of the ADF.
