"Sam is another player who embodies the culture we have endeavoured to build at this club," said Warriors director of rugby Ryan. "I am delighted he has committed to our long-term future."
"He has continued to show his qualities among a very competitive back-row."
Bristol-born Betty, 28, moved to Sixways from Cornish Pirates in 2011.
"I am delighted to commit my future to a club which has grown enormously over the past 18 months," he said. "I firmly believe that we are on a pathway to success. The players who have experienced the lows here really do recognise the progression we have made."
Worcester have dropped to second in the Championship table, three points behind Bristol, the Warriors' 24-game club-record unbeaten run having come to an end on Saturday when they lost to Jersey.
Worcester Warriors flanker Sam Betty has signed a new, undisclosed-length contract with Dean Ryan's promotion-chasing Championship side.