The Argentine swamp rat (Scapteromys aquaticus) is a semiaquatic rodent species from South America.

[2] It is found in northeastern Argentina and Paraguay, where it lives in freshwater marshes and along the southern coast of the Río de la Plata estuary, as well as in woodland.

[2] According to the IUCN Red List of Threatened Species in 2008 the Argentine swamp rat was classified as least concern because of "its wide distribution, presumed large population, and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category.

"[1] These rodents are found in low, flooded grasslands, salt marshes and any area with standing water.

[3] Argentine swamp rats are found scattered through the Rio de la Plata basin and other areas in east-central Argentina, south coastal Brazil, southern Paraguay, and Uruguay.