Soil stabilization may be defined as modifying soil parameters using chemical or physical processes to improve the engineering quality of the soil. The soil stabilization method aids in achieving the essential soil qualities for building operations. Expansive soils, also known as swelling soils or shrink-expand soils, are soils that swell and shrink in response to changes in moisture content. As a result, major soil distress ensues, resulting in serious damage to the underlying structure. The impacts of polypropylene fiber on the geotechnical parameters of locally accessible Black Cotton (BC) soil from Haveri city, Karnataka, India, were investigated in this study. The soil sample was subjected to different tests to determine its consistency limits, specific gravity, compaction, California bearing ratio, unconfined compressive strength, and shear strength. These experiments were carried out on both non-stabilised and stabilised soil by substituting 0%, 0.50%, 1%, 1.50%, 2%, 2.50%, and 3% of polypropylene fiber. The results show that polypropylene fiber improves several geotechnical parameters at various soil replacement percentages. 2.5% replacement is the best solution and an optimum replacement for different geotechnical-related works using this BC soil. The Correlation between the different parameters was also determined from the analysis.