Rubin's 82 tackles led all NFL defensive linemen last season. He was in the final year of his contract, and his new deal is through the 2014 season. The 310-pounder never stops moving on the field and his work ethic and upside convinced the Browns to invest in him for three more seasons.
Financial terms were not immediately available.
The Browns remain in talks with running back Peyton Hillis on a new deal. Hillis, who rushed for nearly 1,200 yards last season, is making $555,000 this season.
Before extending Rubin, the Browns signed Pro Bowl tackle Joe Thomas to a seven-year, $84 million deal and extended tight end Evan Moore's contract by two years. Moore caught a touchdown in Cleveland's 27-17 loss Sunday to Cincinnati in the season opener.