Caçapava do Sul is a Brazilian municipality in the state of Rio Grande do Sul, located on the banks of the Camaquã River. As of 2020, the city has an estimated population of 33,548. It was the 2nd capital of the Piratini Republic from 1839 to 1840. The economy depends primarily on the mining industry. Caçapava do Sul produces 80% of the calcareous rock mined in Rio Grande do Sul. For many years it was Brazil's major producer of copper and is still an important center of copper mining.