Abstract: The biodegradable tampon disposal bag is a biodegradable, fluid resistant and sealable package for receiving used tampons and other feminine hygiene products for disposal thereof. The tampon disposal bag is formed as an envelope having a pair of longitudinally opposed, closed side edges, an open upper end, and a closed lower end. A flap is secured to the open upper end of the envelope for covering and sealing the open upper end when a used tampon is received within the open interior of the envelope. An adhesive seal or the like is provided on the flap, for securing the flap against the envelope once the tampon has been received therein. The envelope and the flap are both formed from a biodegradable and fluid resistant material, such as low-density polyethylene.