The Bahia tyrannulet is about long and weighs . The sexes have the same plumage. Adults have a buffy stripe from the
lores that becomes creamy whitish past the eye, a buffy
eye-ring, and a dusky line through the eye that continues to the rear and sweeps around the dark yellowish ear
coverts. Their crown, nape, back, and rump are bright olive-green with a grayish center to the crown. Their wings are dusky olive with pale yellow edges on the flight feathers. Their wing
coverts have yellow tips that form two
wing bars. Their tail is dusky olive with thin yellowish olive-green edges. Their throat and breast are dirty whitish with pale yellow flecks. The rest of their underparts are medium yellow with faint olive markings on the sides of the breast and flanks. Both sexes have a dark brown iris, a long, pointed, brown bill with a pearly whitish base to the
mandible, and pale gray legs and feet. ==Distribution and habitat==