"Underwater" is a single by Canadian electronic music group Delerium, featuring Australian singer Rani Kamal (daughter of Kamahl) on vocals.

It was the second single released from the album, Poem, and reached number nine on the Billboard Hot Dance Club Play chart in the U.S.

The album version of the song has a slow, ambient arrangement focused primarily on strings performances.

Like nearly all Delerium singles to date since "Silence", the single release put greater emphasis on a number of trance remixes commissioned by Nettwerk Music Group to promote the song through club play.

Notable remixers featured on the various releases of the single include Above & Beyond, Rank 1, Hydrogen Rockers (an alias of Dirty Vegas), and Peter Luts (of Ian Van Dahl and Lasgo).