Lint is the common name for visible accumulations of textile fibers, hair and other materials, usually found on and around clothing. Certain materials used in the manufacture of clothing, such as cotton, linen, and wool, contain numerous, very short fibers bundled together. During the course of normal wear, these fibers may either detach or be jostled out of the weave of which they are part. This is the reason why heavily used articles, such as shirts and towels, become thin over time and why such particles accumulate in the lint screen of a clothes dryer.

Because of their high surface area to weight ratio, static cling causes fibers that have detached from an article of clothing to continue to stick to one another and to that article or other surfaces with which they come in contact. Other small fibers or particles also accumulate with these clothing fibers, including human and animal hair and skin cells, plant fibers, and pollen, dust, and microorganisms.

The etymology of the modern word "lint" is related to "linting", the term used for the cultivation of the shorter fibers from the cotton plant (Gossypium), also called "lint", from which lower-quality cotton products are manufactured. Lint is composed of threads of all colors, which blend hues and may appear to be a uniform grey.

Cotton lint, or cotton linters, is a byproduct of the process of ginning cotton, consisting of the silky fibres that remain attached to the seeds of the cotton plant, as well as other more coarse fibres. This material may be purified and used for such purposes as the manufacture of paper.

Dryer lint is lint generated by the drying of clothes in a clothes dryer; it typically accumulates on a dryer screen. Underwriters Laboratories recommends cleaning the lint filter after every cycle for safety and energy efficiency. Failure to clean the lint filter is the leading cause of home clothes dryer fires.

Navel lint (also known by names such as navel fluff, belly button lint, belly button fluff, and dip lint) is an accumulation of fluffy fibers in the navel cavity often found at the beginning and end of the day. Cloth fibers are scraped by body hair via friction, which ratchets the fibers in the direction of hair growth.

Pocket lint (also known as gnurr) is debris including bits of fabric as well as small shreds of paper and tissue that are often found in pockets. It may sometimes be caused by running the clothing through a washing machine one or more times, causing the pocket lining or contents to compact and shred.

As pocket lint is an amalgamation of the contents of the pockets, pocket lint can be helpful when determining whether drugs have been previously stored in the pockets, by testing it with various drug tests. In a survival situation, pocket lint can be used as tinder for starting a fire.