The experienced 36 year old has joined up with the club who he played for from seasons 1999 - 2001. He made 75 appearances in two full seasons at the Terriers.
In the three seasons he spent with the Blades he only made a disappointing 17 appearances with the likes of Matt Kilgallon and Chris Morgan in front of him in the pecking order.
Blades boss Kevin Blackwell said: "It's a fantastic move for Chris whom I have always regarded as a terrific professional. A two year contract at a good club with a good manager is great for him and he will do well for them. In fact, I will be putting a few bob on