Sulphur-oxidizing bacteria (SOB) are key microbial agents that transform reduced or elemental sulphur into plant-available sulphate, thereby ameliorating sulphur deficiency in soils, a growing concern across agro-ecosystems globally. Through biochemical oxidation processes, SOB contribute to sulphur nutrition, enhance nutrient availability (e.g., zinc, iron), and may support plant growth promotion via auxiliary mechanisms such as phosphate solubilization and phytohormone production. Empirical studies in soybean, onion, mungbean and other crops demonstrate significant improvements in yield, nutrient content, and stress resilience with SOB inoculation. However, the efficacy of SOB depends critically on soil physico-chemical properties, microbial community context, and formulation stability. This article reviews current understanding of SOB?s agricultural role, highlights recent findings, discusses challenges, and outlines future directions for research and application