Alkaline Trio is an American punk rock band from Chicago, Illinois. The band's current members are Matt Skiba (guitar, vocals), Dan Andriano (bass, vocals), and Atom Willard (drums).

Founded in late 1996 by Skiba, bassist Rob Doran, and drummer Glenn Porter, Alkaline Trio released its debut single, "Sundials", in 1997. Following its release, Doran departed from the band and was replaced by Andriano, who occupied the role of co-lead vocalist alongside Skiba. The band subsequently recorded an EP, For Your Lungs Only (1998), and its debut studio album, Goddamnit (1998). Following the release of the band's second album, Maybe I'll Catch Fire (2000), Porter left the band and was replaced by Mike Felumlee for its subsequent album, From Here to Infirmary (2001).

Backed by the singles "Stupid Kid" and "Private Eye", From Here to Infirmary significantly increased the band's exposure, and its follow-up, Good Mourning (2003), charted highly on the Billboard 200. Good Mourning marked the recording debut of longtime drummer Derek Grant. In 2005, the band released Crimson which expanded upon the band's punk rock influences, with prominent overdubs and additional instrumentation, and continued with this direction on Agony & Irony (2008), which was released on Epic Records.

In 2010, the band released This Addiction on its own label Heart & Skull and Epitaph. Recorded in the band's home town of Chicago, with early producer Matt Allison, the album was a conscious effort by the band to return to their punk rock roots; it became the highest-charting album of their career, debuting on the Billboard 200 at No. 11. In 2011, the band celebrated its 15-year anniversary with the release of Damnesia, which featured new, acoustic-based recordings of songs from across the band's career. The band's eighth studio album, My Shame Is True, was released on April 2, 2013, while their ninth album, Is This Thing Cursed? was released on August 31, 2018, followed by a three track EP titled E.P. on March 19, 2020.

In June 2023, Grant departed from the band after twenty-two years, with Atom Willard being announced as his replacement soon thereafter. Their tenth album, Blood, Hair, and Eyeballs, was released on January 26, 2024.