Flannel is a cloth that is commonly used to make clothing and bedsheets . It is usually made from either wool, wool and cotton, or wool and synthetic fabric. The term "flannel" is also often used to refer directly to the clothing created from the fabric. Clothing made from it is usually worn in cold weather climates due to the warmness that the fabric is known for.

For much of its history, flannel was commonly thought to be the fabric of woodsmen, lumberjacks, and farmers. However, due to the fact that many people in the Pacific Northwest of the United States (especially in Seattle, Washington) have had a tendency to wear it, flannel has become associated with grunge music. This idea was even further popularized by the fact that many grunge musicians (such as members of Nirvana) often wore clothing made from it. For a short time in the early 1990s flannel was thought by some to be a fashion statement (or in some cases an anti-fashion statement).