The band-tailed antwren (Myrmotherula urosticta) is a Vulnerable species of insectivorous bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is endemic to Brazil.

The band-tailed antwren is 9 to 10 cm (3.5 to 3.9 in) long. It is a smallish bird with a short tail. Adult males have gray upperparts with a hidden white patch between the shoulders. Their wings are gray with white-tipped black coverts. Their tail is darker gray with the eponymous wide white band at the end. Their throat and upper breast are black; the rest of their underparts are a paler gray than the upperparts. Adult females have a paler gray face and upperparts than males with white-tipped gray wing coverts. Their throat is white, their sides and flanks gray, and the rest of their underparts pale cinnamon-buff.