Global agricultural productivity is significantly constrained by diverse abiotic stressors, including salt, drought, flooding, extremes in temperature, and biotic stressors like bacteria, fungi, nematodes, etc. To overcome these unfavourable circumstances, multiple exogenous strategies are employed, among which the amendment of Plant growth-promoting bacteria (PGPB) is gaining much attention. PGPB are renewable and environmentally friendly options that mitigate the adverse impact of abiotic and biotic stresses without harming the host plant. Exogenous application of PGPB reduces the intensity of these stresses by associating with the host plants, thereby promoting optimal development. These microbes are more likely to be utilised for stress resistance to meet the agricultural requirements in harsh environments. Additionally, the bacterial inoculants promote crop growth as well as nutrient uptake, which ultimately improves the productivity of the crops. Overall, inoculation of PGPB could be an alternative strategy to replace the chemical fertilisers and agrochemicals since, they additionally play a role in biocontrol. The primary objective of this review is to comprehensively examine the role of plant growth-promoting bacteria (PGPB) in enhancing plant tolerance to abiotic and biotic stresses, and to elucidate the mechanisms through which these microbes improve crop growth, nutrient uptake, and overall agricultural productivity under stressful environmental conditions.