Brenthia pleiadopa is a species of moth of the family Choreutidae first described by Edward Meyrick in 1921.

There is an undefined transverse shade of whitish irroration from the middle of the costa to the middle of the dorsum, strongly excurved in the disc to pass around a transverse-oval discal ring of whitish irroration sometimes centrally tinged with pale brownish.

A rather curved irregular broad fascia of whitish irroration is found from a white dot on the costa at three-fourths to the dorsum before the tornus, partially confluent with preceding in the disc and limited posteriorly by terminal markings.

There is a marginal series of seven black subquadrate spots centred with silvery-metallic dots around the apex and termen, the first small and sometimes obsolescent, the fourth and fifth spots confluent (subapical), others separated by greyish-ochreous linear spaces.

The hindwings are dark grey with an irregular discal spot of whitish suffusion before the middle, as well as a whitish subterminal line represented by a dot on the costa towards the apex, a transverse mark near the terminal streak in the middle, and a small mark on the tornus, as well as a moderate ochreous marginal streak around the apex and upper half of the termen, edged anteriorly on the apical portion by a pale silvery-blue mark.