On August 29, 2008, the Carolina Panthers acquired McCown from the Dolphins for a 7th round pick (#237 overall) in the 2009 NFL Draft.
The move came a day after Panthers quarterback Matt Moore suffered a leg injury.
However, general manager Marty Hurney said that the trade for McCown was not in response to Moore's injury, with Hurney stating "Josh is a guy that we've liked for the last several years when he was in unrestricted free agency."
McCown was the backup to Jake Delhomme for all 16 games in 2008.
He was also the backup for the team's NFC Divisional Round loss to the Arizona Cardinals.
He played in two games in 2008.
He relieved Delhomme late in the fourth quarter of a 24–9 win against the Atlanta Falcons but the only statistics he recorded were three end-of-game kneeldowns.
He also relieved Delhomme early in the fourth quarter of a 34–0 win against the Kansas City Chiefs but the only statistic he recorded was one end-of-game kneeldown.

McCown beat out Moore for the primary backup quarterback job in 2009.
In Week 1 against the Philadelphia Eagles on September 13, McCown entered the game late in the third quarter in relief of Delhomme, who had committed five turnovers.
McCown completed 1 of 6 passes for 2 yards before spraining both his left knee and left foot on the same play early in the fourth quarter.
McCown was then relieved by Moore as the Panthers lost to the Eagles by a score of 38–10.
McCown was placed on injured reserve on September 14, ending his season.
He became a free agent in March 2010.
On August 29, 2008, the Carolina Panthers acquired McCown from the Dolphins for a 7th round pick (#237 overall) in the 2009 NFL Draft. The move came a day after Panthers quarterback Matt Moore suffered a leg injury. However, general manager Marty Hurney said that the trade for McCown was not in response to Moore's injury, with Hurney stating "Josh is a guy that we've liked for the last several years when he was in unrestricted free agency." McCown was the backup to Jake Delhomme for all 16 games in 2008. He was also the backup for the team's NFC Divisional Round loss to the Arizona Cardinals. He played in two games in 2008. He relieved Delhomme late in the fourth quarter of a 24–9 win against the Atlanta Falcons but the only statistics he recorded were three end-of-game kneeldowns. He also relieved Delhomme early in the fourth quarter of a 34–0 win against the Kansas City Chiefs but the only statistic he recorded was one end-of-game kneeldown.
McCown beat out Moore for the primary backup quarterback job in 2009. In Week 1 against the Philadelphia Eagles on September 13, McCown entered the game late in the third quarter in relief of Delhomme, who had committed five turnovers. McCown completed 1 of 6 passes for 2 yards before spraining both his left knee and left foot on the same play early in the fourth quarter. McCown was then relieved by Moore as the Panthers lost to the Eagles by a score of 38–10. McCown was placed on injured reserve on September 14, ending his season. He became a free agent in March 2010.
Josh McCown