The incidence of perioperative neurocognitive disorders (PND) is higher in the elderly patients undergoing surgery. Microglia activation-mediated neuroinflammation is one of the hallmarks of PND. Galectin-1 has been identified as a pivotal modulator in the central nervous system (CNS), while the role of galectin-1 in PND induced by microglia-mediated neuroinflammation is still undetermined. An exploratory laparotomy model anesthetized with isoflurane was employed to investigate the role of galectin-1 on PND in aged mice. Open field test and Morris water maze were used to test the cognitive function 3- or 7-days post-surgery. The activation of microglia in the hippocampus of aged mice was tested by immunohistochemistry. Western blot, enzyme-linked immunosorbent assay (ELISA), and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to elucidate the underlying mechanisms. Galectin-1 attenuated the cognitive dysfunction induced by surgery in aged mice and inhibited microglial activity. Moreover, galectin-1 decreased the expression level of inflammatory proteins (interleukin-1β, interleukin-6, and tumor necrosis factor-α), and prevented neuronal loss in the hippocampus. Galectin-1 inhibited the inflammation of BV2 microglial cells induced by lipopolysaccharide via decreasing the translocation of NF-κB p65 and c-Jun, while this kind of inhibition was rescued when overexpressing IRAK1. Our findings provide evidence that galectin-1 may inhibit IRAK1 expression, thus suppressing inflammatory response, inhibiting neuroinflammation, and improving ensuing cognitive dysfunction. Collectively, these findings unveil that galectin-1 may elicit protective effects on surgery-induced neuroinflammation and neurocognitive disorders. © 2021 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.