Protolychnis trigonias is a moth in the family Lecithoceridae.

The forewings are dark purplish bronzy fuscous, the dorsum marked with obscure whitish-ochreous strigulae.

There is a narrow obscure straight antemedian fascia of whitish-ochreous suffusion and there is a small whitish-ochreous discal spot at two-thirds, as well as a small triangular whitish-ochreous costal spot before three-fourths.

The hindwings are pale whitish ochreous, irrorated (sprinkled) with light fuscous except towards the base.

This article relating to the subfamily Lecithocerinae is a stub.