AbstractLignin is a valuable biomaterial. It is both naturally abundant and readily available as a byproduct of the pulping processes, and the proper reprocessing of lignin is an effective way to achieve waste recovery. Lignin fiber mats with web structures can be produced using electrospinning techniques. Such fiber mats are a promising material for use in the production of filter products. This study focused on the development of filter media using electrospun lignin fiber mats. A series of tests were conducted (e.g., particle penetration and pressure drop) to evaluate the filtration efficiency of the proposed filters. The results indicated that the unfavorable mechanical properties of filters solely comprised of a single layer of the lignin fiber mat would have a negative impact on the filtration efficiency of such filters. However, lignin-based composite filters developed with polyethylene oxide (PEO) fiber mats and surgical mask filter layers exhibited a filtration efficiency comparable to filter products that filter out 95% of small particles (N95). Therefore, the proposed lignin-based composite filter has the potential for air filtration applications.