Syllepte brunnescens is a moth in the family Crambidae.

It is found in Brazil (Rio de Janeiro),[1] Panama and Mexico.

The forewings are pale reddish brown, with a paler inner half.

There are traces of a sinuous antemedial line and there is a faint dark spot in the middle of the cell, as well as a discoidal lunule.

The hindwings are pale reddish brown with whitish basal and inner areas.