Jewitt, 27, has spent the past six months playing in the French Elite Championship, having previously made more than 100 first team appearances for the Reds.
Tigers coach Daryl Powell said: “I am delighted that we have been able to secure the services of Lee, a player who I tried to sign at the end of last season.
“He’s a tough and uncompromising player who will add strength and depth to our forward pack at a crucial time of the season.”
Jewitt said: “I can’t wait to get in there and work under Daryl Powell and show what I can do. I’ve got the rest of this year and I’ll knuckle down and if I impress then I could get a longer deal.
“I’m pretty confident that I’ll get it because I’m coming here to play and work hard.”