Abstract <p>The progressive depletion of the stratospheric ozone layer due to anthropogenic activities has led to increased exposure of terrestrial crops including rice to biologically harmful ultraviolet-B (UV-B) radiation. Rice (<i>Oryza sativa</i> L.), being a major food source for over half of the global population, is particularly vulnerable to UV-B radiation, which adversely affects its morpho-physiological features and biochemical processes. Present study assessed the UV-B stress responses of four rice cultivars, out of which ‘Kalajeera’ and ‘Kalabati’ are relatively resistant whereas ‘Jamuna’ and ‘Lalat’ are sensitive to UV-B radiation. The plants in their seedling stage were exposed to supplemental UV-B radiation for 30 days and morpho-physiological features and fluorescence parameters of plants were studied. Morphological traits such as plant height and leaf area showed minimal variation across treatments, indicating limited short-term morphological sensitivity. However, substantial cultivar-specific differences were observed in key biochemical markers. ‘Kalajeera’ and ‘Kalabati’ demonstrated higher tolerance to UV-B exposure, as indicated by stable or enhanced levels of photosynthetic pigments like chlorophylls and non-photosynthetic protective compounds such as anthocyanins and flavonoids. These responses were further supported by chlorophyll fluorescence spectral analyses, which suggested more efficient energy dissipation mechanisms in the tolerant genotypes. In contrast, rice cultivars like ‘Jamuna’ and ‘Lalat’ exhibited pronounced decline in pigment concentrations under extended UV-B exposure, signifying their susceptibility. These findings emphasize the potential of conventional rice varieties as genetic resources for breeding program to develop UV-B-resilient rice genotypes, offering a sustainable strategy to enhance crop tolerance in the face of climate change-induced UV-B radiation stress.</p>