Recently, there is a growing demand of high-performance, lightweight, and light-permeable air filters due to severe air pollution. Nanofiber air filters have been actively investigated to filter out ultrafine particulate matters (PMs) in air. Among various polymer nanofibers, Nylon-6 nanofibers have been widely adopted to fabricate air filters owing to their mechanical strength and chemical stability. However, the filtering efficiency of the Nylon-6 air filter is relatively low when it has high light transmittance. Thus, a relatively thick nanofiber layer is required to ensure the filtering efficiency, leading to a high pressure drop and low light transmittance. Herein, the fabrication and performance of an air filter made of ferroelectric Nylon-11 nanofibers is introduced. The air filters fabricated with ferroelectric Nylon-11 demonstrate much improved PM filtering efficiency due to their spontaneous polarization. Specifically, for inorganic PMs, a higher filtration efficiency of approximate to 70% is obtained for trapping PM2.5 using the filter with 80% light transmittance, which is approximate to 20% higher compared to that of the Nylon-6 air filter with the same light transmittance. Particularly, the Nylon-11 air filter exhibits higher quality factors for both organic and inorganic PMs owing to its high filtering efficiency and breathability. The approach introduced herein is a simple route for fabricating high-performance air filters.