The Australian Government has announced a series of senior command changes within the Australian Defence Force (ADF), subject to approval by the Governor-General, with the appointments due to take effect from July 2026.
Chief of Navy Vice Admiral Mark Hammond AO RAN is set to be appointed Chief of the Defence Force (CDF), replacing Admiral David Johnston AC RAN, who will retire when the change of command occurs in July.
Vice Admiral Hammond has served in the Royal Australian Navy for 40 years, including postings on frigates and in submarines, and has commanded submarines and the Australian Fleet. He has been Chief of Navy since 2022. The government said his experience will be relevant to Defence priorities including Australia’s planned acquisition of conventionally armed, nuclear-powered submarines under AUKUS and the delivery of the Navy’s future surface combatant fleet.
Admiral Johnston has served in the ADF for more than 48 years across Navy and joint appointments. The government said he played a key role in the design of Australia’s future force and in the ADF’s implementation of the 2024 National Defence Strategy, and has held senior operational leadership roles including Chief of Joint Operations and Chief of the Defence Force.
Lieutenant General Susan Coyle AM CSC DSM, currently Chief of Joint Capabilities, will be appointed as the new Chief of Army. Lieutenant General Coyle will be the first woman to command the Australian Army.
Lieutenant General Coyle enlisted in the Army Reserve in 1987 and has held command and senior roles including Head Information Warfare, Commander Forces Command, Commander Joint Task Force 633, Commander 6th Brigade, Commander Task Group Afghanistan and Commanding Officer 17th Signal Regiment.
She will replace Lieutenant General Simon Stuart AO DSC, who is retiring. The government said Stuart was the first Chief of Army to begin his career as a soldier and played a role in preparing the Army for changes following the 2024 National Defence Strategy.
The next Chief of Joint Capabilities will be appointed at a later date.
Rear Admiral Matthew Buckley AM CSC RAN will be appointed, on promotion, as Chief of Navy. Buckley has served in Oberon and Collins class submarines, commanded HMAS Collins and the Submarine Force, and was Head of Nuclear Submarine Capability at the Australian Submarine Agency before becoming Deputy Chief of Navy in January 2025.
The government said the statutory appointments will be presented to the Federal Executive Council.
Prime Minister Anthony Albanese said the appointments would take effect from July, adding: “From July we will have the first ever female Chief of Army in the Australian Army’s 125 year history.”
Deputy Prime Minister and Defence Minister Richard Marles said the outgoing leaders had overseen significant decisions, including Defence’s response to the Royal Commission into Defence and Veterans’ Suicide, work on AUKUS and Navy transformation, and engagement with international partners.
Image: Lieutenant General Susan Coyle AM CSC DSM pictured presenting at PNT2026 in Sydney. Credit: MySecurity Media.
