The increased use of agrochemicals imbalances the biological system, and future agriculture’s reliance on these will degrade soil health and render the production system susceptible and unstable, affecting the fiscal system. To mitigate adverse effects, microorganisms are increasingly recognised as solutions for preserving productive capacity, ensuring sustainable production, and maintaining economic stability. Microbial inoculants are considered a viable approach for improving agricultural sustainability by fostering soil health, nutrient cycling, and plant growth. This chapter addresses the formulation of microbial inoculants, encompassing the microbial strain selection, growth media, and delivery systems, as well as the problems related to their stability, scalability, and efficacy in the field. We examine the functions of various microorganisms in enhancing plant development, mitigating diseases, and improving resilience to environmental stressors. Furthermore, it underscores the practical uses of microbial inoculants, encompassing application techniques and case studies demonstrating their impact on crop output and soil health. This chapter assesses the economic and environmental benefits and disadvantages of microbial inoculants across many agricultural systems and settings. Finally, we outline prospective research paths, emphasising the necessity for comprehensive field trials, the development of customised inoculant formulations, and strategies that overcome regulatory and market challenges to enhance the adoption of microbial inoculants in sustainable agricultural practices.