To investigate the effect of post-harvest light irradiation on the accumulation of flavonoids and limonoids, harvestedNewhall navel oranges were continuously exposed to light-emitting diode (LED) and ultraviolet (UV) light irradiationfor 6 days, and the composition and content of flavonoids and limonoids in the segments were determined usingUPLC-qTOF-MS at 0, 6, and 15 days after harvest. In total, six polymethoxylated flavonoids (PMFs), fiveflavoneO/C-glycosides, seven flavanone-O-glycosides, and three limonoids were identified in the segments. Theaccumulation of these components was altered by light irradiation. Red and blue light resulted in higher levels ofPMFs during exposure periods. The accumulation of PMFs was also significantly induced after white light, UVBand UVC irradiation were removed. Red and UVC irradiation induced the accumulation of flavone and flavanoneglycosides throughout the entire experimental period. Single light induced limonoid accumulation during exposureperiods, but limonoid levels decreased significantly when irradiation was removed. Principal component analysisshowed a clear correlation between PMFs and white light, between flavonoid glycosides and red light and UVC,and between limonoids and UVC. These results suggest that the accumulation of flavonoids and limonoids in citrusis regulated by light irradiation. White light, red light and UVC irradiation might be a good potential method forimproving the nutrition and flavor quality of post-harvest citrus.