This is a list of tributaries of the Río de la Plata, or rivers of the La Plata Basin. Tributaries and sub-tributaries are hierarchically listed in order from the mouth of the Río de la Plata upriver. The terms "right" and "left" indicate on which side of the main stem river a tributary is located, from the perspective of looking downriver, following standard river bank terminology usage. Countries are identified in abbreviated form: AR for Argentina, UY for Uruguay, PY or PA for Paraguay, BR for Brazil, and BO for Bolivia.