Lieutenant general Susan Coyle was named Australia's Chief of Army following a three-decade career during which she has served in the Solomon Islands, Afghanistan and the Middle East.

"Her achievement means that she will be the first woman to command a service in Australian history," Marles told reporters.

"And it is a deeply historic moment. As Susan said to me, you cannot be what you cannot see."

Australia's army is in the throes of a major transformation, equipping itself with long-range firepower, drones and other modern combat tools.

Coyle stressed her experience in areas such as cyber-warfare.

"This breadth of experience provides a strong foundation for the responsibilities of command and the trust placed in me," she said.