Mohair (pronounced ) is a fabric or yarn made from the hair of the Angora goat. (This should not be confused with Angora wool, which is made from the fur of the Angora rabbit.) Both durable and resilient, mohair is notable for its high luster and sheen, and is often used in fiber blends to add these qualities to a textile. Mohair takes dye exceptionally well. It feels warm in winter as it has excellent insulating properties, while its moisture-wicking properties allow it to remain cool in summer. It is durable, naturally elastic, flame-resistant and crease-resistant. It is considered a luxury fiber, like cashmere, angora, and silk, and can be more expensive than most sheep's wool.

Mohair is composed mostly of keratin, a protein found in the hair, wool, horns and skin of all mammals, but mohair's special properties are unique to the Angora goat. While it has scales like wool, the scales are not fully developed, merely indicated. Thus, mohair does not feel the same way common or standard wool does.

Mohair fiber is approximately 25–45 microns in diameter. It increases in diameter with the age of the goat, growing along with the animal. Finer, softer hair from younger animals is used (for example) in scarves and shawls; the thicker, coarser hair from older animals is more often used for carpets and in heavy fabrics intended for outerwear.

The term mohair is sometimes used to describe a type of material used for the folding roof on convertible cars. In this instance, mohair refers to a form of denim-like canvas.