The timing of formation of the Three Gorges, a critical capture point on the Yangtze River, has been debated for more than a century. In this paper, we review the existing evidence and apply two sedimentary provenance proxies (Pb isotopic compositions of detrital K-feldspar and detrital zircon UPb ages) to date its incision based on samples from the early Cretaceous to Quaternary western Jianghan Basin and from the Neogene Yangtze Gravel, both located downstream of the Three Gorges. We show that from the early Cretaceous to the late Eocene, the western Jianghan Basin was mainly fed by the proximal sources, including the Qinling orogen and the Huangling dome. Similarly, from the latest Oligocene to the Miocene, local paleo-rivers supplied the Yangtze Gravel, mainly from the nearby Tongbai-Dabieshan. By the late Pliocene, the Jianghan Basin was fed by a river delivering sands with a Pb isotopic character indistinguishable from that of the modern Yangtze River. These provenance indicators suggest that the Three Gorges was cut through after the late Miocene (~10 Ma) but prior to the late Pliocene (~3.4 Ma). Cretaceous-Cenozoic deposits from the Jianghan Basin and the Yangtze Gravel have a detrital zircon UPb geochronology signature indistinguishable from that of the modern Yangtze River. It is inferred from this that the detrital zircon provenance signal has effectively been homogenized by complex transportation/recycling processes in the Yangtze Craton.