The Governorate of the Río de la Plata (1549-1776) (Spanish: Gobernación del Río de la Plata, pronounced [go?e?na'sjon ðel 'ri.o ðe la 'plata]) was one of the governorates of the Spanish Empire. It was created in 1549 by Spain in the area around the Río de la Plata.
It was at first simply a renaming of the New Andalusia Governorate and included all of the land between 470 and 670 leagues south of the mouth of the Río Santiago along the Pacific coast. After 1617, Paraguay was separated under a separate administration (Asunción had been the capital of the governorate since Juan de Ayolas.)
After the founding of the Viceroyalty of Peru in 1542, the governorate was since its birth under its authority until the formation of the independent Viceroyalty of the Rio de la Plata in 1776. Similarly, it was under the jurisdiction of the Royal Audience of Charcas until the formation of the independent Royal Audience of Buenos Aires from 1661 to 1671 and after 1783.