Alexisonfire (pronounced "Alexis on fire") is a five-piece Canadian post-hardcore band that formed in St. Catharines, Ontario in 2001. They describe their music as "the sound of two Catholic high-school girls in mid-knife-fight" (a reference to their song "A Dagger Through the Heart of St. Angeles", also the inspiration for their debut album cover art). When the band emerged in late 2001, it was enough to impress critics as well as earning their self-titled debut album a platinum certification in Canada. The band has released three subsequent successful studio albums since then: Watch Out! in 2004, Crisis in 2006, and Old Crows/Young Cardinals in 2009, each achieving platinum certification in their native country. Plus three special edition live albums from Manchester Academy, Birmingham Academy, and Brixton Academy. Their accolades include a 2005 Juno Award for New Group of the Year.
In August 2011, vocalist George Pettit posted a message to fans on the band's official website stating that, following the departure of two members, that they would issue several special releases and complete a farewell tour before parting ways.
On March 9, 2015, the band announced a reunion tour, their first since their farewell tour in 2012, including dates at Reading and Leeds festivals, Sonic Boom, Heavy Montréal, X-Fest and Riot Fest. On September 19, 2015, at Riot Fest in Toronto, the band announced their official reunion, although in a post on their official Facebook page afterwards, the band clarified that despite the fact they were "as good friends as they had ever been", there were "no immediate plans" for the future.
The band was the headline act for the 2017 UNIFY gathering in Australia and later announced a small tour across Australia and New Zealand with The Dirty Nil which took place in January 2017.