The Royal Cornwall Hospitals' is one of 20 Trusts across England set to benefit from a £1.8 billion cash boost announced by the government.
The £100 million (£99.9m) coming to the Royal Cornwall Hospital will be the biggest ever single investment Cornwall has seen in local health services.
Kate Shields has been supported by local MPs in pushing the case for investment since becoming RCHT's Chief Executive a year ago.
"This is fantastic news for Cornwall.
"It means we will be able to build facilities to give the next generation the best start in life and bring together services so that our clinical teams can provide brilliant care.
"We can't wait to get started!"
RCHT Chief Executive, Kate Shields
The £100 million investment will see the construction of a new building between the existing Tower Block and Trelawny Wing.
This will house women's and children's services including maternity, neonatal care and gynaecology.
Treliske's new hospital unit will house women's and children's services like maternity, neonatal and gynaecology and be built between the Tower Block and Trelawney Wing
These will be moved from the Princess Alexandra Wing; a building that has been criticised during Care Quality Commission inspections and which, due to structural defects, has a limited life-span.
"Our recent refurbishments to keep the old building going, and to give families now the very best that we can, were always carried out with a bigger scheme in mind in the years to come.
"Knowing the new build is now going to be a reality is an amazing boost for us all and such brilliant news for families and our future generations".
Head of Midwifery, Jane Urben
The investment is excellent news, too, for children's services which will transfer from the top floors of the Tower Block to the new building.
"It is more than 20 years since there has been any major investment in children's facilities at the hospital and their co-location with maternity and neonatal services will allow our teams to work more effectively, to provide safer care and to meet national guidelines. It really is fabulous news!"
Clinical Matron, Mary Baulch
NHS Kernow Clinical Commissioning Group Chief Officer, Jackie Pendleton welcomed news of the investment.
"We're absolutely delighted Cornwall and the Isles of Scilly is getting this vital cash injection.
"Not only will it improve care for local people but modern facilities are bound to attract new staff and a development of this size will bring associated jobs and wider benefits to our local economy".
NHS Kernow, Jackie Pendleton
The building will also become the new main entrance for the hospital with plans for changes to the layout of roads and a pedestrian zone to improve the environment and accessibility.
The next step will be for plans to be further developed and a building programme determined.