<p>Coffee husk, a rich and renewable source of cellulose—the most abundant natural polymer on earth—offers significant potential for sustainable material development. Instead of being discarded as waste with possible environmental consequences, coffee husk can be transformed into valuable cellulose-based materials. In this study, we successfully established a comprehensive multi-stage process for fabricating cellulose aerogels from coffee husk. The fabrication process began with the extraction and purification of cellulose from the coffee husk. The purified cellulose was then blended with hydroxyethyl cellulose (HEC) as a binder and glass wool (GW) as reinforcing fibers. This mixture was subsequently freeze-dried to obtain the cellulose aerogel. To impart hydrophobicity, the aerogel was surface-functionalized using chemical vapor deposition (CVD) with methyltrimethoxysilane (MTMS) as the sole precursor. The resulting coffee husk-based cellulose aerogels exhibited low densities ranging from 0.049 to 0.092&#xa0;g/cm³, high porosity up to 95.62%, and consistent hydrophobicity across both the surface and internal cross-section. The highest measured water contact angles (WCA) were 134° and 130°, respectively. In terms of performance, the aerogels demonstrated promising oil absorption capacity (up to 16.86&#xa0;g/g), low thermal conductivity (0.039–0.047 W/m·K), and effective sound absorption in the mid-to-high frequency range, including the range most sensitive to human hearing. Additionally, the aerogels showed encouraging mechanical resilience, with compressive stress reaching up to 106.1&#xa0;kPa at 25% strain. Overall, these unique properties—combined with the eco-friendly nature of coffee husk—position the developed cellulose aerogel as a promising green candidate for future applications in oil spill remediation and thermal and acoustic insulation.</p> Graphic Abstract <p></p>