This study investigates the preparation and characteristics of polypropylene (PP) composites reinforced with hemp natural fiber processed with sodium hydroxide (NaOH). The hemp fiber, known for its biodegradability and environmental sustainability, was chemically treated to enhance its adhesive properties. The composites were prepared using the compression molding method, with varying weight percentages of hemp fiber (0, 10, 20, and 30 wt%). The mechanical and thermal properties of the composites were evaluated using ASTM standards, including tensile strength, flexural strength, and thermo-gravimetric weight loss. The results showed that the 30 wt% hemp fiber composite exhibited superior mechanical and thermal properties, with tensile and flexural strengths of 47 ± 1 MPa and 69 ± 2 MPa, respectively, and a lower thermal mass loss of 6%. These enhanced properties make the PP composites suitable for applications such as automotive roof frames. The study highlights the importance of chemical processing in improving the performance of natural fiber-reinforced composites.This study investigates the preparation and characteristics of polypropylene (PP) composites reinforced with hemp natural fiber processed with sodium hydroxide (NaOH). The hemp fiber, known for its biodegradability and environmental sustainability, was chemically treated to enhance its adhesive properties. The composites were prepared using the compression molding method, with varying weight percentages of hemp fiber (0, 10, 20, and 30 wt%). The mechanical and thermal properties of the composites were evaluated using ASTM standards, including tensile strength, flexural strength, and thermo-gravimetric weight loss. The results showed that the 30 wt% hemp fiber composite exhibited superior mechanical and thermal properties, with tensile and flexural strengths of 47 ± 1 MPa and 69 ± 2 MPa, respectively, and a lower thermal mass loss of 6%. These enhanced properties make the PP composites suitable for applications such as automotive roof frames. The study highlights the importance of chemical processing in improving the performance of natural fiber-reinforced composites.