Ablett, 23, is the only Rhino to feature in every game this season and his existing deal was due to run out at the end of the season.
The Middleton and Hunslet Parkside amateur will now remain at Headingley for the 2010 season.
He said: “We are having some good times at the Rhinos and playing for Leeds is all I have ever known. This is where I have grown up and I am very much enjoying my rugby this year and I’m looking forward to next year as well.
Ablett made his Rhinos debut in July 2004 and has since made 71 appearances, scoring 13 tries.
“I have had my problems with injuries in the past but to be ever present this season has been great. That has given me a consistent run in the team and the chance to get some form together.
“I am learning so much from the game time I have got recently and the playing alongside the guys we have in our team and I know I can still improve even further.”
Ablett played in Leeds’ Grand Final wins in 2007 and 2008, and he’ll be hoping the Rhinos can make it a hat trick this year.
Head Coach Brian McClennan said: “I am delighted that Carl has agreed a new deal for next season. Carl is an integral player in our team which has been shown over the past few seasons but his consistency and versatility. His best years are still ahead of him and it is good news for Leeds Rhinos that we will continue to see him grow and develop here at Headingley Carnegie.”