Citrus by-products are an important potential high source of valuable compounds such as dietary fiber. In this study, dietary fiber was obtained from citrus by-products by water bath extraction. The drying behavior of the citrus by-product samples was investigated under hot-air drying and vacuum drying. The drying experiments were conducted at drying air temperatures of 50, 60, and 70 °C. The drying curves obtained using experimental data were fitted to 10 models reported in literature. The comparison of the correlation coefficient (R2) and reduced chi-square (χ 2) values of the 10 models shows that the Logarithmic model exhibited the best fitting for hot-air drying, whereas the Wang and Singh model exhibited the best prediction of moisture transfer in vacuum drying. The changes in color and functional properties of the two types of dried dietary fiber were also analyzed and regarded as quality indices that affect the drying quality of the product