Chuck is the third studio album by Canadian rock band Sum 41. The album was released on October 12, 2004. It was the last album to feature guitarist Dave Baksh before his departure from Sum 41 on May 11, 2006. Baksh later rejoined the band in 2015. Chuck peaked at No. 2 on the Canadian Albums Chart and No. 10 on the US Billboard 200, making it the band's highest-charting album until it would be surpassed by Underclass Hero in 2007.

The album's title is named after a volunteer UN peacekeeper named Chuck Pelletier who was in the Democratic Republic of the Congo where Sum 41 was filming a documentary for War Child Canada. Fighting broke out during production, and Pelletier helped the band evacuate their hotel during the fighting, as he was staying at the same hotel.

The album's lyrical content has been described as darker and more mature than the band's previous work. It also had a different sound, mixing punk rock and melodic hardcore with heavy metal. The album proved to be a success, receiving acclaim from both critics and fans, as well as selling over five million copies. Singles such as "We're All to Blame" and "Pieces" gained success on the Canadian and American charts, and the album won a Juno Award for "Rock Album of the Year" in 2005.