Pyroclasts is the ninth studio album by American drone metal band Sunn O))). The album was released through Southern Lord Records on October 25, 2019. Pyroclasts was recorded and mixed by Steve Albini (Nirvana, Neurosis, Godspeed You! Black Emperor) entirely using analog tape. In addition to Greg Anderson and Stephen O'Malley, the album features collaborators Tos Nieuwenhuizen, Tim Midyett and Hildur Guðnadóttir.

Pyroclasts was written and recorded alongside what has been described as a "sister album" or a "fraternal twin" album titled Life Metal that was released six months earlier on April 26, 2019. Sunn O))) plus additional collaborators live recorded a new 11-minute improvised drone session at the start or end of each day during the recording of Life Metal. Pyroclasts is a collection of four of those tracks. The title refers to volcanic airborne pyroclastic rock.