Sustainable agriculture is a global imperative to address food security and environmental conservation challenges. Plant Growth-Promoting Bacteria (PGPB) have emerged as vital players in sustainable agricultural practices due to their multifaceted roles in enhancing plant growth, nutrient uptake, stress tolerance, and disease resistance. This comprehensive review paper explores the diverse facets of PGPB and their potential applications in sustainable agriculture. The review begins by elucidating the mechanisms underlying PGPB-plant interactions, including the production of phytohormones, nutrient solubilization, and biocontrol activities. This review delves into the intricate signaling networks involved in PGPB-induced systemic resistance, shedding light on the molecular pathways driving plant defense responses. Moreover, this review discusses the pivotal role of PGPB in mitigating abiotic stresses such as drought, salinity, and heavy metal toxicity, highlighting their contributions to climate-resilient agriculture. In addition to their direct effects on plant health, PGPB also foster soil health by improving nutrient cycling, organic matter decomposition, and soil structure. This review explores the potential of PGPB as biofertilizers, biopesticides, and biostimulants in integrated pest management and precision agriculture systems. The review paper also evaluates the challenges and limitations associated with PGPB utilization, including formulation, field application, and microbial competition. It highlights recent advancements in biotechnological approaches, such as metagenomics and synthetic biology, to optimize PGPB performance and compatibility. Furthermore, the ecological implications of PGPB application in sustainable agriculture are discussed, emphasizing the need for responsible and environmentally friendly practices. Ethical considerations related to genetically modified PGPB strains and their potential impact on native microbial communities are addressed. Moreover, harnessing PGPB for sustainable agriculture holds significant promise in addressing the pressing challenges of food security and environmental sustainability. This review provides a comprehensive overview of PGPB's multifaceted roles, mechanisms of action, and potential applications, while also underscoring the importance of responsible and eco-friendly approaches in realizing the full potential of PGPB for a resilient and sustainable agricultural future.