The widespread production of plastics, coupled with inadequate disposal and degradation practices, has led to pervasive environmental contamination. Plastics, composed of diverse synthetic polymers, gradually fragment into microplastic particles smaller than 5 mm through physical, chemical, and biological processes. These pollutants originate from two primary sources: primary microplastics, intentionally manufactured for commercial use, and secondary microplastics, formed through the breakdown of larger plastic debris. While most research has focused on marine microplastic pollution, terrestrial ecosystems—particularly soil—remain underexplored despite being significant sinks for microplastic accumulation. Sources such as sewage sludge, landfills, agricultural mulching films, fertilizers, and municipal wastewater contribute to the infiltration of microplastics into soil matrices. Soil ecosystems host complex and diverse microbial communities, which are sensitive to microplastic presence. The interaction between microplastics and soil microbiota can alter microbial abundance, diversity, and functional dynamics, depending on the type and concentration of microplastics involved. Notably, certain microorganisms exhibit the capacity to degrade microplastics into environmentally benign byproducts, offering potential pathways for bioremediation. This chapter provides a comprehensive overview of microplastic contamination in soil, emphasizing its ecological impact on microbial communities and the mechanisms of microbial degradation. It also highlights critical knowledge gaps and proposes directions for future research to better understand and mitigate microplastic pollution in terrestrial environments.