Proserpinus clarkiae, or Clark's sphinx, is a moth of the family Sphingidae.

It is known from British Columbia and Washington south through California to Baja California, east to Idaho, Wyoming and Utah.

The forewing underside basal orange colour is vestigial or absent.

Adults are on wing from mid-March to June in one generation per year.

They feed on the nectar of various flowers, including Salvia columbariae, Asclepias cordifolia, Ribes aureum, Dipterostemon capitatus, Clarkia, Vicia, Cirsium and Stachys species.