Syllepte mildredalis is a moth in the Crambidae family. It was described by Schaus in 1927. It is found in the Philippines (Luzon). The wingspan is 32-37 mm. The wings are wood brown with fine, darker brown lines. The forewings have a sinuous antemedial line from the median to the inner margin, a point in the cell and a short streak on the discocellular. The postmedial line is inbent from the costa, bluntly outcurved from below vein 5 to vein 2, retracted toward the end of the cell, angled and sinuous to the inner margin. The hindwings have the postmedial line bluntly outcurved between veins 5 and 2.