Heteragrion denisye sp. nov. (Zygoptera: Heteragrionidae) is described and diagnosed on specimens collected near a Vereda (i.e. palm swamp) area of the National Park of Serra da Canastra, Minas Gerais, Brazil (-20.2323, -46.6085, 1305 m, 25 x 2018, Vilela, Koroiva, Nobrega & Lera leg.). This species is unique within the genus and it is easily distinguished from congeners due to its blue coloration pattern and cerci morphology, which is robust and presents a reduced apical portion, longer on most Heteragrion species.