James has played 144 NRL matches after making his debut for the Titans in 2010.
The 29-year old has struggled through injuries in recent times, playing just six games in 2019 before rupturing his ACL during the 2020 pre-season.
The veteran is thrilled to begin the next chapter of his career.
“I’m looking forward to the challenge of heading to Canberra and working with Ricky Stuart and the Raiders squad,” James told raiders.com.au.
“The Titans have been a wonderful club for me, and I’ll be forever grateful for what they’ve done for my career.”
Raiders recruitment and high performance director Peter Mulholland added: “We know what Ryan can bring to our club with his football and leadership.”
“He’s a tremendous talent who leads by example on and off the field and we believe he will be valuable addition to our forward pack, particularly for some of our up and coming players.”