Cerradomys marinhus, also known as Marinho's rice rat, is a rodent species from South America. It is found in Minas Gerais, Brazil. It was formerly known as Oryzomys marinhus, but was transferred to the new genus Cerradomys in 2006.
Cerradomys marinhus is a brown rat with black lines along its back, a gray- to yellowish-buff venter, and a bicolored, scarcely-haired tail. It measures in length, not including the tail which is an additional . Its skull is robust and large. The species' diploid chromosome number is 56. All that is known about its reproduction is that pregnant rats have been found during both dry and rainy seasons, and in each case 2 to 4 embryos were present.
The preferred habitat of C. marinhus is cerrado in flooded grasslands and semideciduous forest.