The club also have the option of extending the 31-year-old’s by a further two years at the end of the current campaign.
“I’m really excited to be joining Castleford Tigers,” Bailey said.
“I’ve been really impressed with the set up here and I’m confident I’ll fit in well at this family club.
“I really like the work Daryl is doing here and I’m looking forward to getting down to business and pushing for a place in the team.
“I want to put my reputation behind me now and start a fresh and I hope the fans here get behind me. Having played here at the Jungle the atmosphere is always immense and I can’t wait to pull on the shirt and get out there.”
Cas coach Daryl Powell was delighted to add such an experienced player to his squad at a crucial time of the season.
“I am delighted to welcome Ryan to the club,” said Powell.
“He is a proven Super League player, who I am confident we will see the best of.
“Our pack has been very good this season, and Ryan will add to our options and provide consistency within our squad.
“He comes to us motivated and with a point to prove, and I look forward to working with him.”