Gypsum is widely recognized in the construction industry for its favorable attributes, including fire resistance, thermal insulation, and workability. However, its broader application is often hindered by inherent drawbacks such as brittleness, low mechanical strength, and limited moisture resistance. In response to these challenges—and in alignment with global efforts toward sustainable material development, this research proposes the integration of wood dust, a biodegradable and abundantly available byproduct of wood processing, as a reinforcing filler. Composites were formulated with wood dust at varying weight fractions (0wt%, 15wt%, 30wt%, and 45wt%) and were fabricated through a standardized process of mechanical mixing, molding, and oven curing. Mechanical properties, specifically flexural and compressive strength, were evaluated in accordance with ASTM standards, alongside density assessments to determine the impact of filler content on material weight. The findings present compelling evidence that the addition of wood dust significantly reduces composite density, enhancing the lightweight nature of the material desirable feature in many construction applications. Notably, a filler content of 15wt% yielded the most favorable mechanical performance, with flexural strength increasing by 34.7% (from 3.34 MPa to 4.50 MPa) and compressive strength improving by 21.5% (from 6.68 MPa to 8.10 MPa). However, higher concentrations of wood dust (30wt% and 45wt%) led to a decline in mechanical performance, attributed to increased porosity and the disruption of mineral matrix continuity. These results underscore the importance of optimizing wood filler content to balance mechanical strength with material efficiency.