Underworld is the ninth studio album by American progressive metal band Symphony X. It was released on July 24, 2015 through Nuclear Blast, and released in Japan on August 24. The album's first single, "Nevermore", premiered on May 22, 2015, followed by the second single "Without You" on June 19. They were both officially released on July 22, 2015. The band's guitarist, founder and main songwriter, Michael Romeo, said he was against releasing separated tracks of the album, since it was written to be "a whole".

Symphony X is an American progressive metal band from Middletown, New Jersey. Founded in 1994, the band consists of guitarist Michael Romeo, keyboardist Michael Pinnella, drummer Jason Rullo, lead vocalist Russell Allen and bassist Michael LePond.