Nettle Stinging Leaf (Urtica dioica), Stinging nettle or common nettle, is a herbaceous perennial flowering plant, native to Europe, Asia, Northern Africa, and North America, and is the best-known member of the nettle genus Urtica. The leaves and stems are very hairy with non-stinging hairs and also bear many stinging hairs (trichomes), whose tips come off when touched, transforming the hair into a needle that will inject several chemicals: acetylcholine, histamine, 5-HT (serotonin), moroidin, leukotrienes, and possibly formic acid. This mixture of chemical compounds cause a painful sting or paresthesia from which the species derives its common name, as well as the colloquial names burn nettle, burn weed, burn hazel.

It grows in temperate and tropical wasteland areas around the world. The plant has been naturalized in Brazil and other parts of South America. It grows 2 to 4 meters high and produces pointed leaves and white to yellowish flowers. The genus name Urtica comes from the Latin verb urere, meaning 'to burn,' because of these stinging hairs. The species name dioica means 'two houses' because the plant usually contains either male or female flowers.

Nettle is used in shampoo to make hair more glossy and is often found in other skin care applications.