The Sincorá antwren (Formicivora grantsaui) is a small passerine bird of the genus Formicivora in the family Thamnophilidae, the typical antbirds. It is endemic to a small area of eastern Brazil. The bird was not described as a new species until 2007 (coincidentally, another species was also described from the same region in 2007, the Diamantina tapaculo). The binomial name commemorates the German-born naturalist Rolf Grantsau who collected a specimen in 1965 that was recently identified as this species.