Fiber abbreviations, sometimes referred to as fabric abbreviations, are short letter combinations that refer to a specific type of fiber used in the fabric(s) of a garment. Generally, these abbreviations consist of two or three letters derived from the name of the fiber.

Fiber abbreviations are mainly used for informational purposes related to garment care or garment construction. Fiber abbreviations are often used on care labels which are small sheets or pieces of fabric that are usually designed to be as compact as possible. In order to be concrete but compact, fiber abbreviations are used to quickly communicate the fiber contents found in the fabric of the garment. Abbreviations are particularly common for garments with multiple fibers or fiber blends. Sometimes the abbreviation is given in combination with the full name of the fiber.

The abbreviations of fiber names have no worldwide standardization and different countries or brands might use different abbreviations. However, a generally accepted overview of commonly used fibers is: