Pele's hair (closest modern Hawaiian translation: "lauoho o Pele") is a volcanic glass formation produced from cooled lava stretched into thin strands, usually from lava fountains, lava cascades, or vigorous lava flows. It is named after Pele, the Hawaiian goddess of volcanoes.

Mentions of this type of lava can be found in 18th Century Hawaiian newspapers where it is called "Lauoho o Pele," "Lauoho Pele," and "Lauoho ehuehu a Pele."

Wind often carries the light fibers high into the air and to places several kilometers away from the vent. It is common to find strands of Pele's hair on high places like treetops, radio antennas, and electric poles.

Pele's hair has been produced by volcanoes around the world, for example in Nicaragua (Masaya), Italy (Etna), Ethiopia (Erta’ Ale), and Iceland, where it is known as nornahár [ˈnɔ(r)tnaˌhauːr̥] ('witches' hair'). It is usually found in gaps in the ground, mostly near vents, skylights, ocean entry, or in corners where Pele's hair can accumulate.

It is not recommended to touch Pele's hair, because it is very brittle and very sharp, and small broken pieces can enter the skin. Gloves should be worn while examining it.

Pele's hair may occur along with Pele's tears. They indicate to volcanologists information about the eruption, such as the temperatures and the magma's path to the surface. Plagioclase starts to crystallize from the magma of Pele's hair at around 1,160 °C (about 2120 °F). Also, the shape of the tears can provide an indication of the velocity of the eruption, and the bubbles of gas and particles trapped within the tears can provide information about the composition of the magma chamber.