This article is about the Cthulhu Mythos deitiy. Abhoth is also the name of a death metal band; see Abhoth (band).

Abhoth (nickname: the Source of Uncleanness) is a fictional character, an Outer God from H. P. Lovecraft's Cthulhu Mythos. A resident of N'kai, the underground realm of the Cthonian pantheon, Abhoth is described as a dark grey, horrid protean mass. He is said to be the ultimate source of all miscreation and abomination.

Obscene monsters constantly form in Abhoth' gray mass and crawl away from their parent; however, Abhoth's tentacles and limbs grab many of them, pulling them back and devouring them. Abhoth has a twisted and cynical mind, and possesses the ability to telepathically communicate with others near him.

"[H]e descried a sort of pool with a margin of mud that was marled with obscene offal; and in the pool a grayish, horrid mass that nearly choked it from rim to rim. Here, it seemed, was the ultimate source of all miscreation and abomination. For the gray mass quobbed and quivered, and swelled perpetually; and from it, in manifold fission, were spawned the anatomies that crept away on every side through the grotto. There were things like bodiless legs or arms that flailed in the slime, or heads that rolled, or floundering bellies with fishes' fins; and all manner of things malformed and monstrous, that grew in size as they departed from the neighborhood of Abhoth. And those that swam not swiftly ashore when they fell into the pool from Abhoth, were devoured by mouths that gaped in the parent bulk." __ Clark Ashton Smith, The Seven Geases

Abhoth does not have any human worshippers, although an inhuman cult, known as the Unclean Ones, led by Yeb, is devoted to him.

The demon lord Juiblex in the Dungeons & Dragons role-playing game is likely derived from Abhoth.