<p>The development and evaluation of biodegradable composites, made from poly(lactic acid) (PLA) reinforced with date palm fibers, was investigated, focusing on leveraging natural resources to reduce environmental impact. The effects of fiber length and weight percentage on the mechanical and physical properties of the composites were examined. Samples were fabricated using compression molding with varying fiber lengths (1, 2, and 3) and fiber weight percentages (30, 40, and 50 wt%). Tensile properties, including strength and elastic modulus, were measured, and an analytical model was used to predict the elastic modulus of the composites, with experimental results compared to theoretical predictions. The findings revealed that at 30 wt% of fibers, increasing fiber length improved both tensile strength and elastic modulus. However, at higher fiber content (40 and 50 wt%), longer fiber lengths resulted in a decrease in these properties. The analytical model showed an average prediction error of compared to experimental data. These results demonstrate the potential of date palm fibers as an effective and sustainable reinforcement for PLA-based composites, presenting a promising approach to developing environmentally friendly materials with desirable mechanical properties. These composites could find applications in packaging, automotive parts, and construction materials, offering sustainable alternatives to conventional plastics.</p>