<p>Sustainable agriculture increasingly relies on eco-friendly strategies to reduce dependence on synthetic fertilizers and pesticides while enhancing soil fertility and crop resilience. Among plant growth-promoting rhizobacteria, <i>Bacillus subtilis</i> has emerged as a versatile and resilient microorganism with multifaceted applications in agriculture. This review summarizes current knowledge on the role of <i>B. subtilis</i> in improving soil health, promoting plant growth, and contributing to environmental sustainability. Its beneficial effects are mediated through multiple mechanisms, including nutrient solubilization, phytohormone and siderophore production, enhancement of soil microbial diversity, and suppression of phytopathogens via antimicrobial metabolites. Additionally, its endospore-forming ability ensures long-term survival under diverse agroecological conditions. Recent research highlights the potential of <i>B. subtilis</i> in biofertilization, biocontrol, organic waste recycling, and bioremediation of contaminated soils, thereby reinforcing its importance for the circular bioeconomy. The findings underline the importance of integrating <i>B. subtilis</i>-based bioformulations into large-scale agricultural practices to enhance crop productivity, restore soil health, and reduce negative environmental impact. Future perspectives include optimizing strain-specific applications, elucidating molecular interactions with plants, and advancing biotechnological innovations for sustainable agricultural and food systems. By leveraging its ecological resilience and biotechnological potential, <i>B. subtilis</i> serves as a cornerstone of sustainable agriculture and a vital contributor to the transition toward environmentally friendly food production systems.</p> Graphical Abstract <p></p>