Sustainable agriculture plays a crucial role in addressing the agricultural demands of today's world, offering solutions that conventional farming often fails to achieve. This approach leverages farming techniques that fully utilize environmental resources while ensuring environmental safety, resulting in eco-friendly and healthy agricultural products. Microbial populations are fundamental to the processes that enhance the strength and productivity of agro-ecosystems. Numerous studies have improved our understanding of the diversity, dynamics, and importance of soil microbial communities and their beneficial roles in agricultural productivity. This review focuses on the contributions of plant growth-promoting rhizobacteria (PGPR) and cyanobacteria to sustainable agriculture. An ideal agricultural system should be sustainable, enhance human health, benefit the environment, and produce sufficient food for the growing global population. The use of biofertilizers can reduce the reliance on urea, prevent soil organic matter depletion, and significantly lower environmental pollution. Cyanobacteria and PGPR serve as excellent model systems, providing biotechnologists with novel genetic materials and bioactive compounds for various agricultural and environmental applications. These microorganisms offer an environmentally sustainable approach to enhancing crop production and soil health.