<p>The Jiangnan orogenic belt (JOB) is a world-class tungsten belt and important gold polymetallic belt, hosting over 250 vein Au–(Sb)–(W) deposits with gold resources of &gt; 970 t. However, the absolute age of the gold deposits in the JOB has not been reliably determined due to the lack of suitable minerals for dating. This study presents LA–ICP–MS U–Pb age data on hydrothermal apatite coevel with gold mineralization from the newly discovered Shiwu gold deposit, combined with in-situ apatite geochemistry and pyrite sulfur isotopes, to constrain the ore-forming material sources and determine deposit genesis. Mineralogical observations reveal that native gold is closely associated with pyrite, arsenopyrite, galena, and sphalerite. Notably, apatite not only exhibits a clear spatial association with Au-bearing pyrite and other sulfides but also contains mineral inclusions such as galena, pyrite, arsenopyrite, chalcopyrite, and particularly native gold. Furthermore, the Shiwu apatite shows saddle-shaped REE patterns, weak negative Eu anomalies and high contents of Mn and Sr, which are consistent with those of hydrothermal apatite in other Au (Sb) deposits, indicating its hydrothermal origin and coeval formation with gold mineralization. The apatite ²⁰⁶Pb/²³⁸U age of 168.6 ± 5.7&#xa0;Ma and the calculated δ³⁴S_H2S values of the hydrothermal fluids with a narrow range of 2.61 to 4.51‰ suggest a magmatic origin for the ore-forming materials. Integrating with regional geological data, we propose that Shiwu in the Jinshan gold orefield is a magmatic-hydrothermal gold deposit possibly associated with a porphyry Cu–polymetallic system.</p>