Six new Kielmeyera species (Calophyllaceae) are presented here (K. cataractae, K. colibri, K. doceana, K. inopinata, K. oreophila, and K. stevensii), all from the Atlantic Forest in southeastern Brazil, from the states of Espírito Santo, Minas Gerais, and Rio de Janeiro. Complete descriptions, illustrations, and morphological comparisons with the most similar species for each new species are provided. We also estimated their conservation status according to IUCN criteria. Additionally, an identification key for Kielmeyera species with pollen grains in monads and usually ciliated sepal margins from Atlantic Forest and a comparison table are provided.