The retailer will open at least four stores in Bury St Edmunds, Craigavon, Salisbury and Teesside Park as part of this investment.
Primark said that the stores will increase its selling space by more than 160,000ft² and create at least 850 jobs for local communities.
The company also plans to expand and invest in its existing stores, as well as relocate its stores in Bradford and High Wycombe to ‘higher-profile’ locations.
In addition, Primark will add a dedicated Primark Home space to its Liverpool store, having previously installed a Primark Home space in its Merry Hill store in the West Midlands.
In line with its commitment to improving its in-store experience, the retailer will upgrade its stores on high streets, shopping centres and retail parks.
It will also update the décor and fixtures in its stores, as well as continue its roll-out of LED lighting across its UK store portfolio.
Primark chief executive Paul Marchant said: “The UK is our biggest market and, as we continue to grow and expand our business internationally, we remain as committed as ever to investing in our stores to offer more customers our great value clothing, beauty, homewares and much more.
“Busy towns and cities benefit us all – we want to see thriving high streets and shopping centres where people come together and enjoy spending time.
“Through today’s investment, we’re playing a part in ensuring that UK retail continues to grow and thrive and give people another reason to visit their local high street.”
This investment builds on the Click + Collect trial that Primark launched across 25 UK stores last week.
The retailer currently operates a network of 190 stores with more than 30,000 employees across the UK.