Slope failures pose significant risks to infrastructure in hilly and engineered terrains. This study presents a comprehensive numerical investigation into slope stabilization using micropiles, conducted with PLAXIS 2D. Key parameters—micropile length (15 m to ground level), diameter (0.2–0.5 m), horizontal placement (Xp/X = 0.25–0.75), number of layers (1–7), and slope angle (1V:1H to 1.4V:1H)—were systematically analyzed. Soil properties were derived from laboratory testing of site-collected samples. Results demonstrate that five micropile layers at uniform spacing extending to ground level, with a 0.5 m diameter, yield the highest Factor of Safety (FoS), outperforming configurations with additional layers. Micropile efficacy was found to be highly sensitive to both insertion geometry and layering pattern. This study identifies optimized reinforcement layouts that ensure structural stability while remaining cost-effective, offering practical guidance for safer and more economical slope stabilization in geotechnical practice.