Hippotion irregularis is a moth of the family Sphingidae. It is known from forests from Liberia to Congo, Uganda and western Kenya. It is also found in the Usambara area of Tanzania. The length of the forewings is 33–36 mm. The body and forewings are olive-ochreous. The forewings are slightly mottled with brown and marked with a few faint oblique lines, evenlycurved from the inner margin to the apex and crenulate near the margin. There is a small blackish stigma and a series of blackish dots at the veins running from the middle of the inner margin to the apex. The hindwings are dark brown with a pale spot at the tornus.