Cotton is a soft, fluffy staple fiber that grows in a capsule or protective covering around the seeds of cotton plants of the genus Gossypium in the mallow family (Malvaceae). The fiber consists almost entirely of cellulose and may contain small amounts of waxes, fats, pectins and water. Under natural conditions, the cotton bolls promote seed dispersal.

The plant is a shrub native to tropical and subtropical regions around the world, including the Americas, Africa, Egypt, and India. The greatest variety of wild cotton is found in Mexico, followed by Australia and Africa, and has been independently domesticated in the Old and New Worlds.

The fiber is most commonly spun into yarn or thread and used to make soft, breathable and durable textiles. The use of cotton to make textiles dates back to prehistoric times; fragments of cotton cloth dating back to the fifth millennium BC have been found in the Indus Valley Civilization, as have fabric remnants from Peru dating back to 4200 BC. Although it was cultivated in ancient times, it was not until the invention of the cotton gin, which reduced production costs, that it became widely used, so that today it is the most common natural fiber used in clothing.

World production is currently estimated at about 25 million tons or 110 million bales per year, representing 2.5% of the world's cultivated area. India is the largest producer of cotton in the world. The United States has been the largest exporter for many years.