A new endemic goblin spider genus Guaraguaoonops is erected to include two new soft-bodied oonopid species from Brazil: the type species, G. hemhem, distributed in the states of Maranhão, Piauí, and Ceará, and G. humbom, known only from Piauí. These spiders are unique among oonopids and easily diagnosed by the flattened carapace with a porrect clypeus, modified lateral setae on the carapace in both sexes, and male with a sinuous, flattened distal cheliceral projection and palp with ventral conical tegular projection. These species probably occupy a soil cryptic habit and are found in dry sand of “cerrado” areas in northeastern Brazil.