The cytoprotective effects of 6'-O-galloylpaeoniflorin against injury and death of human HaCaT keratinocytes resulting from ultraviolet B radiation were investigated. 6'-O-galloylpaeoniflorin exhibited the capacity to scavenge intracellular reactive oxygen species (ROS) generated by ultraviolet B radiation. 6'-O-galloylpaeoniflorin also attenuated ultraviolet B-induced oxidative macromolecular damage to DNA, lipids, and proteins, decreasing the number of DNA strand breaks, the level of 8-isoprostane (a biomarker of lipid peroxidation), and the level of protein carbonylation. Moreover, 6'-O-galloylpaeoniflorin rescued HaCaT cells from ultraviolet induced cell death, by downregulating the mitochondrial apoptotic pathway. Taken together, these results indicate that 6'-O-galloylpaeoniflorin has the potential to be developed as a medical agent against ROS-mediated skin diseases.