This study investigates the effects of incorporating paper waste into mycelium-based green composites (MBCs) to enhance their physical and mechanical properties. MBCs are produced using lignocellulosic substrates (corn husk and sawdust) and mushroom mycelia of the genus Lentinus sajor-caju TBRC 6266. The addition of paper waste, which is rich in cellulose, significantly improves the density of MBCs. For example, MBCs made from sawdust with 40% paper waste had a density of 322.73 kg/m³, while those made from corn husk with 40% paper waste had a density of 274.51 kg/m³. The inclusion of paper waste also increased the compression, bending, and impact strength of MBCs by over 20% when 20% paper waste was added to corn husks. However, adding paper waste to sawdust did not improve MBC properties. MBCs made from corn husk with 10% paper waste absorbed less water than those without paper waste, while those with more paper waste showed higher shrinkage. The tensile strength of MBCs was not improved by adding paper waste, indicating that further research is needed to enhance this property. The study highlights the potential of using paper waste to improve MBCs for applications in sustainable packaging and home decor. The findings suggest that MBCs can be a viable alternative to traditional materials due to their biodegradability and environmental benefits. Future research should focus on optimizing the properties of MBCs to fully realize their potential in various applications.This study investigates the effects of incorporating paper waste into mycelium-based green composites (MBCs) to enhance their physical and mechanical properties. MBCs are produced using lignocellulosic substrates (corn husk and sawdust) and mushroom mycelia of the genus Lentinus sajor-caju TBRC 6266. The addition of paper waste, which is rich in cellulose, significantly improves the density of MBCs. For example, MBCs made from sawdust with 40% paper waste had a density of 322.73 kg/m³, while those made from corn husk with 40% paper waste had a density of 274.51 kg/m³. The inclusion of paper waste also increased the compression, bending, and impact strength of MBCs by over 20% when 20% paper waste was added to corn husks. However, adding paper waste to sawdust did not improve MBC properties. MBCs made from corn husk with 10% paper waste absorbed less water than those without paper waste, while those with more paper waste showed higher shrinkage. The tensile strength of MBCs was not improved by adding paper waste, indicating that further research is needed to enhance this property. The study highlights the potential of using paper waste to improve MBCs for applications in sustainable packaging and home decor. The findings suggest that MBCs can be a viable alternative to traditional materials due to their biodegradability and environmental benefits. Future research should focus on optimizing the properties of MBCs to fully realize their potential in various applications.