Introduction Taraxacum mongolicum Hand.-Mazz. is rich in dietary fiber and has been reported to exhibit hypoglycemic activity. This study investigated the effects of lactic acid bacteria (LAB)-fermented dandelion Jiangshui (JS) on glucose metabolism and pancreatic and renal histopathology in hyperglycemic mice. Methods Lactiplantibacillus plantarum A1 and Lacticaseibacillus paracasei strains A3 and L2, previously isolated from traditional JS by our research team, were used to prepare dandelion JS by fermentation. Forty-five 5-week-old male C57BL/6 mice were randomly assigned to a normal control group, a model group, and a JS intervention group. Mice in the JS group received LAB-fermented dandelion JS by gavage, whereas mice in the other groups received an equal volume of normal saline for 14 consecutive weeks. Body weight, glucose-related biochemical indicators, and pancreatic and renal histopathology were monitored throughout the experiment. Results Compared with the model group, the JS group showed attenuated increases in blood glucose, higher levels of the anti-inflammatory cytokine IL-10, increased hepatic antioxidant enzyme activities, including glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT), lower malondialdehyde (MDA) content, and less severe pancreatic and renal lesions. Discussion These findings suggest that LAB-fermented dandelion JS may have potential to improve glucose regulation and alleviate inflammation, oxidative stress, and pancreatic and renal injury in hyperglycemic mice.