Stoner metal is a subgenre of metal music that combines elements of doom metal with elements of psychedelic rock and blues rock to create a melodic yet heavy sound. Like stoner metal's close relative genre stoner rock, riffs are often groovy and psychedelic, while the tempo of the music as a whole is generally slow to mid paced. The guitar tuning is kept low and, unlike stoner rock, there is an additional emphasis on a bass-heavy sound. This form of music was first pioneered in the early 1990s by such bands as Kyuss, Sleep, and Cathedral.
Several of the genre's earliest establishers shared a common characteristic in that both band members and fans alike were frequent marijuana users. This fixation on cannabis, which can also be found within the lyrics of many songs, when combined with the heavy and psychedelic sound of the music gave the genre its now defining nickname as stoner metal. Due to the similarities in styles, some stoner metal bands will borrow and incorporate certain aspects of sludge and vice versa.

As is the case with stoner rock, grunge seemed to have particularly had a hand in the foundation of stoner metal as well; as such bands including Alice In Chains, Melvins and Soundgarden had strong psychedelic leanings besides heavy/doom metal tendencies, sometimes even reaching (dissonat) sludge metal. Soundgarden was metallic and post-punky whilst still retaining prominent psychedelic/blues elements; with even doom metal elements present, very similar to Black Sabbath and a direct evolution of Led Zeppelin plus punk energy. Later Melvins ventured into stoner territory with the release of "Stoner Witch" in 1994. Perhaps the origin of the "stoner sludge" combination. Alice In Chains appears to be the most obvious and readily identifiable influence on (modern) stoner metal as it is plagued by their signature vocal harmonies and singing style besides riffing heavily inspired by their signature/iconic style and sound.