Three Days Grace is a Canadian rock band formed in Norwood, Ontario in 1992 originally as "Groundswell" and played in various local Norwood backyard parties and area establishments before disbanding in 1995 and regrouping in 1997.
Based in Toronto, the band's original line-up consisted of guitarist and lead vocalist Adam Gontier, drummer and backing vocalist Neil Sanderson, and bassist Brad Walst. In 2003, Barry Stock was recruited as the band's lead guitarist, making them a quartet. In 2013, Gontier left the band and was replaced by My Darkest Days' vocalist Matt Walst, the younger brother of Brad Walst.
Currently signed to RCA Records, they have released seven studio albums, six of which at three-year intervals: Three Days Grace in 2003, One-X in 2006, Life Starts Now in 2009, Transit of Venus in 2012, Human in 2015, and Outsider in 2018. Their seventh studio album Explosions was released on May 6, 2022. The first three albums have been RIAA certified 2× platinum, 3× platinum, and platinum, respectively, in the United States. In Canada, they have been certified by Music Canada as platinum, triple platinum, and double platinum, respectively. The band has 17 No. 1 songs on the Billboard Hot Mainstream Rock Tracks chart and 3 No. 1 hits on Alternative Songs.