Additive manufacturing has revolutionized bio-composite applications by enabling precise material deposition and sustainable production. This study evaluates the mechanical and thermal properties of hemp-reinforced recycled polylactic acid composites fabricated using fused filament fabrication and injection molding. Tensile specimens were produced using both techniques and compared to pure recycled polylactic acid samples. Experimental tests, including thermomechanical analysis, thermogravimetric analysis, differential scanning calorimetry, and tensile testing, were conducted alongside numerical simulations to assess material performance. Results indicate that hemp-reinforced composites significantly outperform recycled polylactic acid in key mechanical properties. Results showed the elastic modulus increased by 21.15%, ultimate tensile strength improved by 33.23%, and the coefficient of thermal expansion decreased by 14.23%. These findings demonstrate that these bio-composites can serve as viable alternatives to synthetic materials in structural applications, reducing plastic consumption by 10% while maintaining superior mechanical integrity. This study paves the way for sustainable composite development in automotive, aerospace, and other high-performance industries.