A new genus of cynipid oak gallwasp, Zapatella Pujade-Villar & Melika, gen. n. (Hymenoptera: Cynipidae: Cynipini), with two new species, Zapatella grahami Pujade-Villar & Melika, sp. n. and Zapatella nievesaldreyi Melika & Pujade-Villar, sp. n., is described from the Neotropics. Zapatella grahami, known only from the sexual generation, induces galls in acorns of Quercus costaricensis and is currently known only from Costa Rica. Zapatella nievesaldreyi, known only from the asexual generation, induces inconspicuous galls in twigs of Quercus humboldtii, and is known only from Colombia.