The South Pacific Convergence Zone (SPCZ) is the dominant precipitation band in the Southern Hemisphere, and variations in its position strongly influence precipitation, tropical cyclones, sea level, and extreme climate events. However, centennial-scale changes in the SPCZ remain poorly understood due to limited instrumental data. Coral oxygen isotope compositions (δ¹⁸O) are ideal proxies for studying the SPCZ, as they sensitively record sea surface temperature and precipitation signals associated with SPCZ shifts. Here, we reconstruct the SPCZ position from 1147 to 2005 CE using monthly resolved coral δ¹⁸O data. Our results reveal strong interannual and decadal variability, primarily modulated by the El Niño–Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO). On centennial timescales, the SPCZ exhibits multi-phase migration, driven by a weakened zonal sea surface temperature gradient. This study highlights the value of coral proxies for long-term SPCZ research and provides a foundation for further investigations into its spatiotemporal evolution and forcing mechanisms.