Argia sertaneja sp. nov. (BRAZIL, Minas Gerais state, Chapada Gaúcha, Grande Sertão Veredas National Park, Vereda lodging (15.iv.2023, 15°11'14.7"S 45°41'01.7"W, 807 m asl, M.M. Souza leg., Coleção Biológica de Vespas Sociais-CBVS) is described, illustrated, and diagnosed. The new species can be separated from its congeners by the wide morphology of male cercus, and shape of female hind lobe of prothorax and mesostigmal lobes.