The first-described articulated Permian sponge from Brazil, representing Hexactinellida, has been recovered from the Lontras Shale in the Campáleo outcrop (Permian, Asselian–Sakmarian), Rio do Sul Formation, Mafra, in southern Brazil. It is assigned to the Hemidiscellidae and identified as Microhemidiscia greinerti n. sp. This fossil represents the first record of articulated sponges in Brazil from the Paleozoic Era, as well as the second species known from this genus. Moreover, it increases knowledge of the order Hemidiscosa, a monotypic group mostly defined by simple characters, which is here considered to comprise one family, Hemidiscellidae (Pennsylvanian-Cretaceous), and two genera, Hemidiscella and Microhemidiscia.