Activated Bleaching Earth or also often called Fuller’s Earth/Activated Bleaching Earth, is a type of clay mine in Asia, England, India, and the United of States. Bleaching earth is any clay material that has the capability to decolorize oil or other liquids without chemical treatment. Bleaching earth consists primarily of hydrous aluminum silicates (clay minerals) of varying composition. Common components are montmorillonite, kaolinite and attapulgite. Small amounts of other minerals may be present in bleaching earth deposits, including calcite, dolomite, and quartz. In some localities bleaching earth refers to calcium Bentonite, which is altered volcanic ash composed mostly of montmorillonite.

In addition to its original use in the fulling of raw fibers, bleaching earth is now utilized in a number of industries. Most important applications make use of the minerals' natural absorbent properties in products sold as absorbents or filters. Modern uses of fuller's earth include absorbents for oil, grease, and animal waste (cat litter) and as a carrier for pesticides and fertilizers. Minor uses include filtering, clarifying, and decolorizing; and as filler in paint, plaster, adhesives, and pharmaceuticals.