帕托斯湖是巴西的湖泊，位于该国南部，由南里奥格兰德州负责管辖，长280公里、宽70公里，面积9,850平方公里，是拉丁美洲第二大潟湖，平均水深3米，最大水深7米。

Lagoa dos Patos (Portuguese pronunciation: [laˈɡo(w).ɐ dus ˈpatus]; English: Ducks' Lagoon) is the second largest lagoon in Latin America and the biggest in Brazil. It is located in the state of Rio Grande do Sul, southern Brazil. It is 174 miles (280 km) long, has a maximum width of 44 miles (70 km), and a total area of 3,803 sq. mi. (9,850 km). It is separated from the Atlantic Ocean by a sandbar about 5 miles (8 kilometers) wide. The navigable São Gonçalo Channel, which enters Lagoa dos Patos near the town of Pelotas, connects Lagoa dos Patos to Lagoa Mirim to the south. The Rio Grande, at the south end of Lagoa dos Patos, forms the outlet to the Atlantic.