A taxonomic treatment of species of Senegalia (Leguminosae, Mimosoideae) from the Atlantic Domain is presented. We recognized the occurrence of 28 species, from about 52 species in Brazil. The species from the Atlantic Domain occur mainly in these physiognomies: Rain Forest (22), Restinga (14) and Semi-deciduous Forest (12). Fifteen species have wide distributions and 11 taxa have restricted areas of occurrence. We developed a dichotomous key, morphological descriptions, illustrations, and distribution maps for the species. The principal diagnostic characters were the shape, number and position of extrafloral nectaries, number of pairs of pinnae per leaf, and inflorescence type. Two new species are described here: S. amorimii and S. grazielae, and three new records were found for the Atlantic Domain: S. kallunkiae, S. limae, and S. santosii.