The pectoral antwren (Herpsilochmus pectoralis) is a Vulnerable species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds".

[2][1] The pectoral antwren was originally described by the English zoologist Philip Sclater in 1857 and given its current binomial name Herpsilochmus pectoralis.

[3] Its relationship to others of its genus is unclear but it apparently is most closely related to the large-billed antwren (H. longirostris), and at least one author has considered them to form a superspecies.

Adult females have a rufous crown, brownish olive upperparts, buffish edges on their flight feathers, and buff sides of their neck and their underparts.

It forages actively and methodically, and usually captures prey by gleaning from leaves, stems, and vines by reaching and sometimes lunging from a perch.

The pectoral antwren's song is a "high, very fast chattering series of 'tututjdrrrrrr' notes, which rise rather sharply at the start and may finish slightly falling-off to an abrupt ending".

"It is still insufficiently known to determine precise threats, but clearance for irrigated and dry field agriculture has removed extensive tracts of deciduous forest."

"Systematic surveys [are] needed in order to determine true extent of the species’ range and population, as well as the best locations for creation of multiple small reserves.