The Jilantai-Hetao Basin is a key transitional zone between the erosional upper and depositional lower reaches of the Yellow River, preserving a continuous record of aeolian-fluvial interactions. However, variations in sediment provenance during the late Quaternary and their driving mechanisms remain poorly understood, particularly the relative contributions of fluvial and aeolian transport processes during this climatically sensitive interval. We systematically investigate these provenance variations in sediments from the Dengkou sub-uplift during the late Quaternary using detrital zircon UPb geochronology. Our results reveal three distinct phases: (1) From similar to 170.41 ka to >74.23 ka, sediments in the Jilantai-Hetao Basin were primarily derived from the western Chinese Loess Plateau (CLP) which was originally Northeastern Tibetan Plateau (NTP)-fed, likely reflecting enhanced erosion and remobilization of pre-existing loess under a strengthened East Asian Summer Monsoon (EASM), followed by fluvial transport via the Yellow River; (2) At similar to 50.24 ka, the source switched to the Gobi-Altay Mountains (GAMs), with GAMs-derived material dominant thereafter, driven by East Asian Winter Monsoon (EAWM) intensification; (3) Last similar to 18.60 ka GAMs dominance in Jilantai-Hetao Basin forced by proximal desert activation and land-use pressure. These quantified shifts offer new insights into monsoon-fluvial-aeolian competition in the upper Yellow River and offer a template for predicting watershed response to future hydro-climatic perturbations.