Underworld is the fourth studio album by Australian band Tonight Alive, released on 12 January 2018.

It is the last album to feature founding member and guitarist Whakaio Taahi, who departed the band upon the record's completion.

[3] The album was recorded in Thailand by producer Dave Petrovic, who has worked on nearly every Tonight Alive release to date.

Underworld is the first album of the band's to be released on Australian independent label UNFD.

It features contributions from Slipknot and Stone Sour frontman Corey Taylor, as well as PVRIS vocalist Lynn Gunn.