The collared gnatwren (Microbates collaris) is a species of bird in the family Polioptilidae, the gnatcatchers. It is found in Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.

The collared gnatwren is approximately 11 cm (4.3 in) long and weighs 10 to 12 g (0.35 to 0.42 oz). The nominate subspecies is brown above and mostly creamy white below. Its head has a brown crown, white supercilium, cheek, and throat, and a thick black line through the eye. The underside has a wide black band across the chest and olive-brown flanks. The sexes are similar. The other subspecies differ in the intensity and in some cases the hue of the upperparts and flanks and the width of some facial markings.