The deal extends Thurston's association with the Cowboys to 2013 and will build a nine-year partnership with the Australian and Origin representative.
Thurston has captained the Cowboys since 2006 and is one of the game's true marquee players, with a playing record that includes 13 matches for Queensland (2005-09), 12 tests for Australia 2006-09, the 2008 World Cup and the Prime Minister's XIII (2006, 2009).
In a further boost to the club, the Cowboys have secured front rower James Tamou for an additional three years.
Tamou joined North Queensland in 2009 from the Roosters Toyota Cup and impressed with a try in his NRL debut in round 8.
Executive Director Peter Parr is delighted with the announcement that both players will be retained by the Cowboys.