In one aspect, a disposable liner for a litter box is provided. The liner includes a base comprising a first end edge, a second end edge opposite the first end edge, a first seam edge, and a second seam edge opposite the first seam edge. The first seam edge and the second seam edge extend between the first end edge and the second end edge. The liner also includes a first side wall coupled to the base at the first end edge, a second side wall coupled to the base at the second end edge, a first end wall coupled to the base at the first seam edge, and a second end wall coupled to the base at the second seam edge. The first end wall comprises an integrally formed first gusset, and the second end wall comprises an integrally formed second gusset.