Deep Six is a compilation album featuring early recordings from several Seattle-based rock bands, originally released in March 1986 (catalog# CZ001). It was the very first release by C/Z Records, preceding by a few months the release of Sub Pop's Sub Pop 100. It is often cited as one of the two earliest records to showcase the "Seattle sound" that would later gain worldwide popularity as grunge (the other being Green River's debut EP Come on Down). The album was reissued as a joint C/Z Records/A&M Records release on April 6, 1994 (catalog # 6971 2400 2).
An alternative version of Soundgarden's "Heretic" appears on the soundtrack for the 1990 film Pump Up the Volume, as well as on the Soundgarden EP Loudest Love; a re-recorded version of Soundgarden's "All Your Lies" (with new drummer Matt Cameron) appears on their 1988 album Ultramega OK and the original appears on the band's 2010 compilation album Telephantasm, while a re-recorded version of "Tears to Forget" (with Cameron) appears on their 1987 EP Screaming Life. Alternative versions of the Melvins' "Blessing the Operation" and "Grinding Process" appear on 26 Songs.