Abiotic stresses, including drought, salinity, extreme temperatures, and heavy metal contamination, significantly impair plant growth and productivity. One of the major consequences of abiotic stress is excessive production of ROS, which leads to oxidative stress. Oxidative stress damages various cellular components, such as lipids, proteins, and nucleic acids, thereby affecting plant morphology, physiology, and overall plant growth. Plants have evolved enzymatic and non-enzymatic antioxidant defense mechanisms to counteract oxidative stress. Microbes, especially plant growth-promoting rhizobacteria (PGPR), play a pivotal role in mitigating abiotic stress in plants through various processes and underlying mechanisms that include biological nitrogen fixation, phosphate solubilization, phytohormone production, and the synthesis of stress-related proteins and other metabolites. Besides, PGPR enhances plant tolerance to abiotic stress by maintaining ion homeostasis, enhancing water uptake and retention, and activating stress-responsive genes and detoxification mechanisms. They also reduce oxidative damage/stress by modulating the ROS scavenging system, including the activities of antioxidants and antioxidant enzymes. The present chapter explores the underlying mechanisms of PGPR mediated alleviation abiotic stress-induced oxidative stress, highlighting their role in enhancing plant resilience. The potential applications in sustainable agriculture are also discussed, emphasizing their importance in developing crops resistance to stress to ensure food security in the face of increasing environmental challenges.