He has signed a two year contract which will keep him at the club until the end of 2014, having agreed a release from the final year of his contract at Huddersfield Giants.
The 34-year old will link up with his former St Helens coach Ian Millward.
“We were in need of someone with that experience and knowledge and that is why we have negotiated an early release of his contract at Huddersfield. He will not only be a valuable player, he’ll also be a great mentor for our younger players. He’s a very good communicator on and off the field and I’m delighted he’ll be coming to Cas.
“People should dismiss his age as he’s been very much injury-free throughout his career and has very good leg speed. He has the capabilities of emulating Steve Menzies well into his late 30s.”