The statue features Billy Boston, Clive Sullivan and Gus Risman who left amateur rugby union in Wales to become legends for professional rugby league clubs in England.
In the ceremony on Friday Sir Billy had his name updated on the plaque to be formally recognised as Sir William John Boston KBE.
Boston’s son Stephen, who attended the event, described it as a “very special day”.
“It means a lot more to my dad coming from Tiger Bay and being honoured in Tiger Bay, it’s always going to be a little bit more special for him,” he said.
Stephen said his dad has had “really fond memories” of growing up in Cardiff.
“When we come down, all he talks about is Tiger Bay,” he added.
Stephen said it had a “special place” in his heart, despite Sir Billy earning acclaim in Wigan for his rugby league exploits.
“He’s lived in Wigan longer than he’s lived here, and he’s been adopted as a Wiganer [someone from Wigan], but in his heart he’s still a Tiger Bay boy and that will never change.”