Denton only joined Worcester Warriors at the start of the season, but is set for a sharp exit after making just 14 appearances so far, with the Tigers his next destination.
The 28-year-old back row forward has won 36 caps for Scotland and has also played for Edinburgh and Bath, and Tigers head coach Matt O'Connor is delighted with the deal.
"He is a top-quality player with a lot of experience at the highest level," O'Connor said.
"He has a useful skill set in possession, he is a physical player, he is a good age profile for us and is just the kind of player we've been looking to add to our options in the forward pack."
Meanwhile, Leicester have also announced that the experienced Mark Bakewell has been appointed as the club's new forwards coach.
"We're incredibly pleased that a highly experienced, successful guy has decided to join the environment," O'Connor told BBC Radio Leicester.
"He's incredibly detailed, got a wealth of knowledge across several competitions and I think he'll add a very methodical, detailed and aggressive approach to what we're trying to do up front."