Southern Decay is a sludge metal band from San Antonio, Texas, formed in 2023, channeling the slow corrosive weight of Southern sludge into the fertile Texas heavy music scene.

Sowbelly is a sludge/doom metal band from Durand, Michigan, active since 2009. They deal in slow, heavy riffs and oppressive atmosphere rooted firmly in the American sludge tradition.

Space Cadaver is a psychedelic sludge metal band from New Orleans, Louisiana, formed in 2017. They channel the city's tradition of swampy, heavy music through hallucinogenic sludge riffs and a warped cosmic aesthetic.

Space Lord is a sludge/stoner/doom metal trio from Kenilworth, New Jersey, formed in 2017, stacking massive fuzzed-out riffs across the heavy spectrum from swampy sludge to slow, weed-charred doom.

Space Weed are a stoner/sludge metal band from Cape Canaveral, Florida, formed in 2021. Their name and location lean into the cosmic joke of launching heavy, slow-burning riffs from the shadow of NASA's launch facilities on the Space Coast.

Spacebeast is a sludge/stoner metal band from Portland, Oregon, formed in 2015. They combine the slow, grinding heaviness of sludge with the lysergic haze of stoner metal, fitting naturally into Portland's well-established heavy underground.

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.