The chapter identifies five social classes in Brazil and traces their origins to colonial times and subsequent immigration. It tries to show that the classes overlap, but are not identical, with habitus types. The study finds six habitus types, which are analyzed in some detail. The habitus types incorporate aspects of a social ontology, while other aspects of social ontology are shared by the overwhelming majority of the Brazilian population. The chapter explores some of the links between class, habitus, and social ontology, with some attention to linguistic behavior. The study is based on more than 600 qualitative interviews, which were conducted in all regions of Brazil in 2015.