Abstract: Tropical sea surface temperature (SST) is primarily responsible for the variation in the East Asian summer monsoon (EASM) system. In recent decades, significant progress has been made in the investigation of the effects of tropical SST anomalies on the EASM. This paper provides a brief review of recent advancements in the study of the influence of tropical air–sea interactions on the EASM and associated mechanisms spanning subseasonal, interannual, and interdecadal timescales. Herein, key developments related to the impacts of phenomena, such as El Niño–Southern Oscillation, tropical Indian Ocean, and Atlantic Ocean, are focused. Additionally, the role of tropical SSTs in connecting the EASM with the East Asian winter monsoon is systematically reviewed. Finally, several issues that need further investigation in the future are proposed, including the impact of tropical SST anomalies on the EASM subseasonal variations, changes in tropical SSTs under global warming, and their impact on the EASM.