The tropical oceans play important roles in the global climate system through ocean transports of heat and freshwater as well as ocean–atmosphere interactions. The developments in observational networks during recent decades have helped us to quantify the strength and variability of most of the ocean general circulations responsible for the transports. Those are discussed in detail in individual sections covering each tropical basin separately with a special emphasis on recent research results. Shallow overturning cells observed in all three tropical basins as well as the deep Atlantic meridional overturning circulation are such examples that are linked to ocean and climate variations on multiple timescales. In addition, tropical ocean–atmosphere interactions associated with oceanic planetary waves cause large-scale climate variations such as El Niño/Southern Oscillation (ENSO), Indian Ocean Dipole, Atlantic Niño, and ENSO Modoki. Recent advances in numerical modeling augmented by in situ and satellite observations are helping the research community to understand ocean process and to predict associated climate variations on seasonal to longer timescales.