Thorburn was traded June 22, 2007 to the Atlanta Thrashers, where he became an everyday player with 73 games played in 2007-08. The forward played in all 82 games in 2008-09 when he ranked second on the team in hits (127). In 2010-11, he led team forwards in blocked shots (71) and ranked third among Atlanta skaters in hits (129). After continuing with the club through its 2011 relocation, Thorburn established himself as both a respected voice in the Jets' dressing room and a contributing member of the Winnipeg community during his six seasons wearing a Jets jersey. In 2014-15, he played in 81 games and helped the Jets reach the playoffs, before he played in all 82 games the following year for the third time in his career. Thorburn played in a total of 10 NHL seasons with the Thrashers/Jets, and he remains the franchise leader in penalty minutes (832), while ranking fourth in games played (709).