Underclass Hero is the fourth studio album by Canadian rock band Sum 41. It is the first of two albums by the band recorded as a three-piece since the departure of guitarist Dave "Brownsound" Baksh the previous year. It was released on July 24, 2007 by Island Records and distributed worldwide by Aquarius Records, the band's final album on the label. In comparison to the heavy metal-inspired style of their previous album Chuck (2004), Underclass Hero marked a return to the band’s pop-punk sound.