Panaeolus cinctulus is a species of mushroom in the family Bolbitiaceae. It is commonly known as the banded mottlegill or weed panaeolus.

Panaeolus cinctulus is widely distributed and can be found in various habitats, including lawns, compost, gardens, and dung. It is a saprotrophic species, meaning it feeds on decaying organic matter, and typically appears from spring to autumn.

Morphologically, Panaeolus cinctulus has a brown to reddish-brown cap that can be conical or bell-shaped, sometimes flattening with age. The cap often features a darker band around the margin, which gives the species its “banded” nickname. The gills are dark and mottled, a characteristic feature of the Panaeolus genus. The stem is slender, often pale to dark brown, and lacks a ring.

Due to its widespread occurrence and psychoactive properties, Panaeolus cinctulus is of interest to both mycologists and those studying the effects of psilocybin.