Around 2,500 shipbuilding jobs are to be safeguarded across the UK after the government awarded the contract for a new class of frigate to a consortium led by Babcock, bringing some of that work to Rosyth.
Hundreds of those jobs will go to Fife under the £1.25bn order for five Type 31 frigates for the Royal Navy, which Boris Johnson said was part of a commitment to "bring shipbuilding home".
The first of the cut-price vessels, which have been designed to keep costs below £250m per ship, is expected to be in the water by 2023.
The government hopes the low cost will help export the frigates to navies around the world.
The ships will be built exclusively in the UK and different elements of the frigates will be assembled and made at various British shipyards. The contract includes 150 jobs for new technical apprenticeships.
Ahead of a formal announcement during a visit to a shipyard on the Thames, Mr Johnson said: "The UK is an outward-looking island nation, and we need a shipbuilding industry and Royal Navy that reflect the importance of the seas to our security and prosperity.
"This is an industry with a deep and visceral connection to so many parts of the UK and to the Union itself.
"My government will do all it can to develop this aspect of our heritage and the men and women who make up its workforce - from apprentices embarking on a long career, to those families who have worked in shipyards for generations.
"I look forward to the restoration of British influence and excellence across the world's oceans. I am convinced that by working together we will see a renaissance in this industry which is so much part of our island story - so let's bring shipbuilding home."
The PM has also appointed Defence Secretary Ben Wallace as the Government's new shipbuilding tsar to enhance the UK's shipbuilding enterprise.
He will look at how the Government can use further education, skilled apprenticeships and graduates to achieve a sustainable skills base for British shipbuilding across the UK.
Mr Wallace said: "These mighty ships will form the next generation of the Royal Navy fleet. The Type 31 frigates will be a fast, agile and versatile warship, projecting power and influence across the globe.
"The ships will be vital to the Royal Navy's mission to keeping peace, providing life-saving humanitarian aid and safeguarding the economy across the world from the North Atlantic, to the Gulf, and in the Asia Pacific."
The vessels will be fitted with the world-leading Sea Ceptor missile system, a range of highly advanced weapon and sensor systems and a combat system with a 4D air and surface surveillance and target indication radar.
They will also have capabilities to operate with a Merlin or Wildcat helicopter.
International Trade Secretary Liz Truss added: "We will make the Type 31 frigate an export success. Like the Type 26 before it, there has been significant interest in the design and capabilities of the Type 31 from around the world.
"Countries are modernising their fleets to safeguard against 21st century naval threats and British-built vessels and maritime technology are in high demand. An outward looking United Kingdom will seize this opportunity as we leave the EU."