An important synoptic system responsible for extreme precipitation in Shandong (EPS) is tropical cyclones (TCs). Enhancing the understanding of the formation mechanisms of TC-induced extreme precipitation is of great significance for disaster prevention and mitigation. This study employs the 1961–2020 best-track data provided by the Shanghai Typhoon Institute of the China Meteorological Administration (CMA) and daily precipitation data from 79 meteorological stations in Shandong during the same period to investigate the key factors and impact mechanisms of EPS caused by northward-moving TCs under different phases of the El Ni?o-Southern Oscillation (ENSO). The results indicate that the key factors determining whether TCs can trigger EPS exhibit significant differences across different ENSO phases. In El Ni?o developing years, the intensified Indian Summer Monsoon (ISM) plays a crucial role in TC-induced EPS events. The active northward-propagating intraseasonal oscillation leads to the coordination between the strong ISM and northward-moving TCs over the western North Pacific, which continuously transports abundant water vapor from the South China Sea and the Bay of Bengal to Shandong. Meanwhile, Shandong is located on the left side of the southwest low-level jet and the right side of the entrance region of the upper-level westerly jet. The dynamic effect of this vertical jet configuration favors the generation of intense ascending motion, thereby causing EPS events. In La Ni?a developing years, the western North Pacific Subtropical High (WNPSH) exhibits a closer association with TC-induced EPS. The anomalous wave source over the Barents-Kara Seas in the preceding period excites a wave train propagating eastward to the mid-latitudes of East Asia, resulting in the westward extension and northward shift of the WNPSH. The WNPSH change steers the TC continuously transport abundant water vapor from the Pacific Ocean to Shandong, providing favorable moisture conditions for extreme precipitation.