Announcing the massive boost on Monday, French President Emmanuel Macron said "to be free, we have to be feared".
The move comes as Russia's war in Ukraine drags into its fifth year, and the Middle East grapples with a widening conflict following US-led strikes on Iran.
In Hobart, the French icebreaker L'Astrolabe docked at the port earlier this week after completing its final Antarctic rotation of the season.
It was joined by the patrol ship Benebig, to mark 400 years since the French navy was founded in 1626.
Speaking in Canberra ahead of the anniversary, France's ambassador to Australia Pierre-Andre Imbert pointed to the millions of his nation's citizens in the Indo-Pacific.
"The main mission of our navy is protecting the French interests and the rights and sovereignty of all our partners," he told AAP.
At the heart of that is protecting maritime freedom of navigation, amid rising regional tensions due to Beijing's expanding influence.
China launched an intercontinental ballistic missile into the Pacific in September 2024, which travelled almost 12,000 km and landed about 700 km away from French Polynesia's Marquesas Islands.
The test sparked concern over the region's increasing militarisation.
Mr Imbert said the French navy helped tackle illegal fishing activity in the Pacific, which posed a major threat to the region's economies.
France is also working with partner nations, including Australia, to crackdown on drug trafficking.Â
It is thanks to the collaboration between the countries that operations to combat transnational crime had been a "tremendous success," the top diplomat said.
But the presence of the French ships went beyond deterrence in the Indo-Pacific, with events held to celebrate scientific exploration.
Mr Imbert said archives documenting the d'Entrecasteaux expedition which explored Tasmania and other Pacific Island nations in the 1790s, were "exceptional" in collecting the testimonies of First Nations people and capturing cultural exchange.
Through collaboration between Australia and France, those archives have been digitised and given to the National Archives of Australia, where they are being translated into English.
