The Paulo Afonso Hydroelectric Complex, also known as the Paulo Afonso Complex, is a system of three dams and five hydroelectric power plants on the São Francisco River near the city of Paulo Afonso in Bahia, Brazil. The complex exploits an 80-metre (260 ft) natural gap on the river, known as the Paulo Afonso Falls. Constructed in succession between 1948 and 1979, the dams support the Paulo Afonso I, II, III, IV and Apollonius Sales (Moxotó) power plants which contain a total of 23 generators with an installed capacity of 4,279.6 megawatts (5,739,000 hp).

The São Francisco River is a large river in Brazil. With a length of 2,914 kilometres (1,811 mi), it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil. It used to be known as the Opara by the indigenous people before colonisation, and is today also known as "Velho Chico".