During a visit to Perth last week ahead of the upcoming WA election, Prime Minister Malcolm Turnbull said the infrastructure would include wharves, jetties and cranes.
"The $100 million investment highlights the critical role Western Australia plays in the nation's shipbuilding and submarine programs," Mr Turnbull said.
The $100 million investment will go towards sustaining defence estate, primarily HMAS Stirling, which is the Royal Australian Navy's (RAN) primary base on the west coast of Australia, and the Henderson shipyard facility. The PM said this investment will ensure the Henderson facility remains world-class and allows for more ships to built at the precinct.
"The new infrastructure will allow more ships to be built and sustained at the precinct, creating and maintaining jobs for the region," he said.
"This means new work for builders, architects, electricians, glaziers and many more - all of whom will be working on developing and maintaining state-of-the-art national security capabilities."
Minister for Defence Industry Christopher Pyne said the government's infrastructure investment would contribute to continuous naval shipbuilding and enhanced sustainment of the RAN Fleet.
"Continuous naval shipbuilding and the development and maintenance of critical infrastructure is also identified as an investment priority in the 2016 Defence White Paper," Minister Pyne said.
"The upgrades will not only ensure the shipyard and companies that own and use the precinct have the infrastructure to support these existing projects, but are also best placed to successfully bid for future shipbuilding and sustainment work."
The Pacific Patrol Boat Replacement Project, being undertaken by Austal, is one of the $306 million projects that will take place at the Henderson facilities.
With this investment, the Department of Defence is now set to spend around $2.4 billion upgrading defence facilities in WA, and a further $1.9 billion over the following decade.
This includes upgrades to HMAS Stirling, Campbell Barracks, RAAF bases Pearce, Curtin and Learmonth, the Harold E Holt Communications Facility, and Yampi Sound Training Area, and enhancing Special Forces capabilities to support the Special Air Services Regiment.