Therme Group will start construction in Manchester next year with tenders set to be invited shortly for the 28-acre site.
And the concept will then be rolled-out to city-centre sites in Wales, Scotland and London.
The resorts combine nature, sustainable technology and culture offering a fun and relaxing experience that also focuses on mental and physical health for visitors.
Guests can experience thermal bathing traditions from around the world alongside wellbeing therapies in a biodiverse natural environment.
Therme Group already operates across Europe. Its latest resort opened in 2016 in Bucharest and welcomes 1.3 million visitors a year.
The UK is now a key focus for the business’s international development programme.
UK Chief Operating Officer, James Mark, said: “Our resorts provide a vital piece of social infrastructure in our cities, creating relaxing and fun places to meet whilst also nurturing mental and physical health.
“Our aim is to ensure that a Therme Group wellbeing resort is within easy reach of 90% of the UK population.”
The company said it is at “an advanced stage of discussion” with local authorities and stakeholders in several locations in Wales, Scotland and London.
Mark said:“We will be locating our resorts within large population centres.
“Now more than ever, people living in cities need opportunities to have relaxing and affordable wellbeing experiences close to home.
“Our concept, creating indoor biodiverse ecosystems that combine pure waters and natural environments, is already hugely popular in a number of European cities and it is a concept that will fundamentally improve the way we will live in the future.”