"Adia" is a Sarah McLachlan song that originally appeared on her 1997 album Surfacing. It was co-written by McLachlan and her longtime producer, Pierre Marchand. "Adia" was the third of four songs from "Surfacing" to be released as a single. The single, released July 7, 1998, contains four tracks: the radio mix of "Adia", the Surfacing mix of "Angel", the original studio version of "I Will Remember You" (as opposed to the live version included on the Mirrorball album, also released as a single), and a live version of "Building a Mystery".
A live version of "Adia" appears on the Mirrorball album.
McLachlan was nominated for Best Pop Female Vocalist at the 1998 Grammy Awards for "Adia", losing to Celine Dion and "My Heart Will Go On"