Plant nutrients are necessary for the development of crops and nutritious food for the world's growing population. Today's soil management methods rely mostly on inorganic chemical-based fertilizers, which pose a significant health and environmental risk. In sustainable farming, bio-fertilizer has been discovered as an option for improving soil fertility and crop output. Because of their potential significance in food safety and sustainable crop production, the use of beneficial microorganisms as bio-fertilizers has become more important in the agricultural industry. Bio-fertilizers may be an essential part of a comprehensive nutrient management strategy. Nitrogen fixers (N-fixers), potassium and phosphorus solubilizers, growth promoting rhizobacteria (PGPRs), endo and ecto mycorrhizal fungi, cyanobacteria, and other helpful microscopic organisms are all frequently employed as bio-fertilizer components. Improved nutrient and water absorption, plant development, and plant tolerance to abiotic and biotic influences are all benefits of using bio-fertilizers. As eco-friendly and cost-effective inputs for farmers, these prospective biological fertilizers would play a significant role in soil production and sustainability, as well as in environmental protection.