Sennius Bridwell belongs to the richest tribe of Bruchinae, Bruchini, subtribe Acanthoscelidina, with more than 60 species distributed in the New World. The larval behavior of Sennius species stands out in being strongly associated with Cassiinae L. seeds (Fabaceae: Caesalpinioideae), especially Senna Miller. Eight species-groups were established for Sennius, but some of them are not well defined. The goal of this contribution is to describe 2 new species from Brazil, both closely related to species currently classified in the guttifer group. The new species are Sennius albopygus sp. nov. (Type locality: Brazil, Goiás, Goiânia) and Sennius solum sp. nov. (Type locality: Brazil, Goiás, Niquelândia). We have host records only for Sennius albopygus, as occurring on Senna alata (Linn.) Roxb. and Senna aculeata (Pohl ex Benth.) H. S. Irwin & Barneby. We also include illustrations and geographical distribution records for these species.