Sphinx adumbrata is a moth of the family Sphingidae. It is known from Mexico. The thorax upperside, head upperside and palpi are grey. There is a narrow, black mesial line on the abdomen upperside with five elliptical, pale yellow spots. The abdomen underside is grey with a mesial black line. The forewing upperside is also grey, with a black basal patch on the hind margin and a black line in the discal cell. The hindwing upperside is grey with diffuse, dark, basal mesial and submarginal bands.