<p>This work presents the development and characterization of lightweight epoxy-based radar-absorbing nanohybrid composites using graphene nanoplatelets (GNP)–coated rice husk ash (RHA) as fillers. The controlled combustion of rice husk produced RHA, an amorphous silica-rich agricultural by-product, which was then ground to an average particle size of ~ 14&#xa0;μm. An irregular, porous, silica-dominated morphology, favourable for adjusting dielectric behaviour, was observed by FESEM and EDS analyses. GNP-coated RHA were prepared by depositing graphene nanoplatelets onto RHA with polyvinyl alcohol as a binder. Composites with 20 wt% RHA (EP:R20), and nanohybrid systems with 5, 10, and 15 wt% GNP coated RHA [EP:R20(G5), EP:R20(G10), and EP:R20(G15) respectively] were characterized and compared with that of neat epoxy (EP). With marginal increase in the density, DC electrical conductivity improved from 1.57 × 10⁻¹² S/cm for neat epoxy to 3.56 × 10⁻¹¹ S/cm for EP:R20(G15). In the X-band frequency range (8–12&#xa0;GHz), the EP:R20(G15) showed maximum reflection losses (RL) of − 41&#xa0;dB. Based on these results, GNP-coated RHA/epoxy nanohybrids can be considered as a promising, affordable, and eco-friendly radar-absorbing material for stealth applications.</p> Graphical Abstract <p></p>