With an increasing number of ocean observations and the development of data assimilation models, the quality of the sea temperature data for the South Pacific has improved greatly. Therefore, many studies of large-scale extratropical ocean-atmosphere interaction and its impact on climate variability have focused on the South Pacific. This review introduces systematic studies of the characteristics of the variability of the South Pacific sea temperature (surface and subsurface sea temperature) anomaly, including the interannual and interdecadal variation in the leading mode, the characteristics of the South Pacific, and the relationships among the South Pacific sea temperature anomaly, El Niño-Southern Oscillation, and Southern Annular Mode. It also considers the impact of the South Pacific sea temperature anomalies on the atmospheric circulation and the impact of the South Pacific on the weather and climate in South America, eastern Asia, and China. On the basis of a review of former studies, important questions that require further study in the future are proposed in order to increase scientists’ understanding of the importance of studies of the South Pacific sea temperature anomaly, which can promote scientific progress regarding the South Pacific sea temperature and its climatic impact.