<p>This research examines the mechanical, morphological, and thermal properties of chrysotile mineral-reinforced linear low-density polyethylene (LLDPE) composites, produced through rotational molding. The research considered finding the optimal fiber loading for improving composite performance. The analysis of Melt Flow Index (MFI) indicated acceptable flow characteristics up to 12 wt.% of chrysotile but product formation success was restricted to 9 wt.% because of brittleness. Thermal stability and flame retardancy were enhanced with filler loading, with melting temperature and glass transition slightly increasing and char residue growing from 4.38% to 14.51% for 9 wt.% composite. Mechanical testing indicated that 3 wt.% chrysotile exhibited the best result, with tensile strength enhanced by 18%, tensile modulus by 51%, flexural modulus by 36%, and impact strength by 10.5%. Increased filler levels (6–9 wt.%) resulted in decreases in tensile and flexural strength, impact resistance, and ductility as a result of fiber clustering and void generations. Morphological characterization verified even fiber dispersal and excellent interfacial adhesion at 3 wt.%, but not at elevated loadings, which showed clustering and poor adhesion. Overall, the optimal reinforcement level was found to be 3 wt.% chrysotile, which had the best balanced combination of mechanical, thermal, and processing properties for rotationally molded LLDPE composites.</p>