Regan Grace has signed for Cardiff for the remainder of the 2024-25 season after completing his move from Bath.
The rugby league convert was targeted by Cardiff head coach Matt Sherratt who is without several injured players.
But the six-month Arms Park contract could be extended beyond this season.
“I’ve always been excited about Cardiff – it’s a big, historical club and a lot of legends have played here,” said Grace.
“Coming back to play on home soil has also always been something I have wanted to do, so to do that in the capital city is a great opportunity.
“I’m very much aware of all the dual-code legends who have played for, or come through, Cardiff, so to follow in those footsteps is pretty cool.”
It is the latest twist in the 28-year-old’s transition from rugby league to union following his surprise inclusion in Wales’ tour Australia last summer.
The former St Helens star was only called into the Wales training squad as an injury replacement, but made his competitive union debut against Queensland Reds, scoring with almost his first touch.