Efficient exploitation of agricultural waste promotes sustainability. Low-cost biodegradable hybrid natural fillers—tamarind seed (TMS) and peanut shell powder (PNS)—were added to vinyl ester (VE) resin using compression molding with filler loadings of 5–30%. Mechanical testing showed 20 wt.% filler provided peak tensile, flexural, and impact strengths (40.3 MPa, 142 MPa, 16 kJ/m2) and increased heat deflection temperature by 50.91%. SEM analysis correlated microstructure to mechanical performance. Adding 20 wt.% hybrid biosolid waste fillers improves mechanical and thermal properties, making the composite suitable for lightweight applications. © 2024 Elsevier B.V., All rights reserved.