Smyths is set to open in the newly built Leckwith shopping site on October 17th.
A spokesman for the company, a leading toy retailer in Ireland, said: "The opportunity to open a store in the wonderful location in Cardiff was too good to miss.
"We have predicted this will be one of our most successful stores. We expect people are going to come from far afield to visit the store in the run up to Christmas. It's in a capital city with a lot of other competitors. It's really going to show how good Smyths is."
The retailer will open in the newly created retail complex alongside other major names including Marks & Spencer, Asda, Costco, ScS and JJB Sports.
Smyths started life in a small newsagents shop in Galway, before expanding into a major toy empire. After conquering much of the Irish market, it has now set its sights on Britain.
As well as visiting the shop, customers will also be able to reserve items on the website, collecting them from the store at their convenience.