The plain-winged antwren (Myrmotherula behni) is a species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds".

[4] The plain-winged antwren's specific epithet honors Wilhelm Friedrich Georg Behn.

Adult males of the nominate subspecies M. b. behni are almost entirely gray, with lighter underparts than upperparts.

Adult females have olivaceous brown upperparts with a grayish tinge on the crown and nape and a somewhat duskier tail.

[3] The plain-winged antwren inhabits the understorey to mid-storey of foothill and lower montane evergreen forest.

It forages singly, in pairs, or in family groups, and almost always as part of a mixed-species feeding flock.

The plain-winged antwren's song is a "series of high, simple, slightly downslurred 'tiuw' notes".