Abstract The desiccation (extreme drying) of rivers has important implications for the broader Earth System. However, the desiccation history and its linkage to climate are rarely known for numerous major river systems, primarily due to difficulties in recognizing desiccation events from available stratigraphic records. Here, using a combination of geochemical techniques (major and rare‐earth element geochemistry, detrital zircon geochronology, and optically stimulated luminescence dating), we demonstrate that the Yellow River, which maintains the highest sediment load on Earth, became desiccated during the Last Glacial Maximum at approximately 20 thousand years ago. This finding implies that transportation of sediments and dissolved constituents to the oceans via the Yellow River may have decreased substantially or ceased during glacials, which would have ramifications for ocean chemistry and biology. Furthermore, our work highlights the importance of desiccated riverbed sediments as potential dust sources during glacial periods, a finding that is different from what is observed today.