Spaisekult is a Vermont-based progressive sludge metal and hardcore band formed in 2022. They meld the caustic, slow-burning density of sludge metal with hardcore's propulsive urgency and progressive metal's structural ambition, operating on the experimental edge of all three genres.

Spanghew is a sludge metal band from Seattle, Washington, formed in 2025. A newly emerged outfit in one of the country's most storied heavy music cities, they carry on the Pacific Northwest tradition of punishing, low-and-slow sludge metal.

Sparrowmilk is a doom and sludge metal band from Cleveland, Ohio, formed in 2017, trafficking in the city's tradition of slow, oppressive heaviness with droning riffs and suffocating atmosphere.

Speaker Eater is an atmospheric sludge and doom metal band from Wausau, Wisconsin, formed in 2011, building massive, slow-burning compositions that blend post-hardcore dynamics with the crushing weight of sludge and the desolate sprawl of atmospheric doom.

Spellchucker is a doom/sludge metal band from Cleveland, Ohio, formed in 2018, delivering slow, oppressively heavy music that fuses traditional doom's despair with sludge metal's abrasive, feedback-drenched textures.

Spewdriver is a Kansas City sludge metal band formed in 2023, churning out oppressive, feedback-soaked riffs rooted in the down-tuned ugliness that defines the genre.

Spirit Guardian is a sludge metal band from Birmingham, Alabama, formed in 2019, drawing on the Southern heaviness and abrasive textures that characterize the region's robust sludge tradition.

Spliff Witch is a doom, stoner, and sludge metal band from Anderson, South Carolina, formed in 2021, delivering hazy, heavy-riffed music steeped in the psychedelic fatigue and swamp-weight of the Southern sludge tradition.

Spliffripper is a doom and sludge metal band from Kalispell, Montana, formed in 2021, offering slow, crushing heaviness from the remote northern Rockies, where the isolation of the landscape matches the oppressive weight of the music.