Felt is a fabric made of wool fibers or animal hair matted together by steam and pressure without spinning, weaving or knitting. Such fibers include wool, fur and certain hair fibers that met together under appropriate conditions because of their peculiar structure and high degree of crimp (waviness).

Wool can produce felting even when mixed with other fibers. Unlike bounded fabrics, felts do not require adhesive substance for their production. Woven fibers made of cotton or wool may be felted, making them thicker and more compact. Such fabrics, sometimes called woven felts, resemble true felts and serve many of the same purposes.

Felt is widely used in the hat industry. It is also used to make slippers and as a novelty fabric garments and drapery. Felt padding is employed in both apparel and furniture.

Industry applications include insulation, packaging, and polishing materials. In Nepal, felt is made by hand with sheep wool. This unique cloth is made in Nepal from centuries in remote Himalayan villages. Traditionally it is used to make rugs to insulate their homes from extreme cold.