<p>The study investigates the fabrication of wood plastic composites (WPCs) via injection moulding, utilizing marble waste particulates (MWP) and corn stalk particulates (CSP) as fillers. By incorporating 50% hybrid particulates (CSP and MWP) into low-density polyethylene (LDPE), notable improvements in thermal conductivity and mechanical properties are observed compared to neat LDPE. In particular, the composites exhibit approximately 120% higher flexural strength, a 26% increase in tensile strength, a significant enhancement of 156% in flexural modulus, and a remarkable 255% increase in tensile modulus. Furthermore, these composites demonstrate superior thermal conductivity by nearly 24% compared to pristine LDPE. Despite these enhancements, the composites maintain low water absorption at 0.16%, with marginal changes in density and a reduction in impact strength by 76.84%. The research showcased the potential of utilizing waste materials such as MWP and CSP in wood plastic composite, offering sustainable and economically viable alternatives for traditional materials. Additionally, the findings highlight the promising prospect of incorporating byproducts from mineral resources such as marble waste as fillers into WPCs, further enhancing their thermal and mechanical properties while promoting environmental sustainability.</p> Graphical abstract <p></p>