Three Days Grace is a Canadian rock band formed in Norwood, Ontario 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 Three Days Grace a four-member band. In 2013, Gontier left the band and was replaced by My Darkest Days' vocalist Matt Walst, who is also bassist Brad Walst's brother.
Signed with Jive Records, Three Days Grace has released six studio albums, each 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. The first three albums have been RIAA certified 2x platinum, 3× platinum, and platinum, respectively, in the United States. In Canada, they have been certified by Music Canada as platinum, double platinum, and platinum, respectively. The band has a string of number one songs on the Billboard Alternative Songs and Hot Mainstream Rock Tracks charts.